ESE's works engine tuner

[ken seeber]

More info on the "drum" charger

http://www.alterego-hardware.com/images/Drum-Charger-Press-Kit-EICMA-EN.pdf

[Frits Overmars]

You know, I've often wondered if the end of the chamber was superimposed into the crankcase, with a membrane the same could be achived, a pulses-varied crankcase volume.Could be done, but that would mean using the crankcase as a pump. And since its dead volume is so big, it is, and would remain to be a very poor pump.
Besides, the gases exiting the tailpipe of an expansion chamber aren't pulsating very strongly any more.
I see more advantage in using the blowdown pulse of one cylinder to pressurize the mixture-filled exhaust duct of an adjacent cylinder that is about to close its exhaust. It's what you see in multicylinder outboard motors where there is no room for multiple expansion chambers. And that primary blowdown pulse would certainly be stronger than the reflected pulse from an expansion chamber.
The trick would be to concentrate as much primary pulse energy as possible onto that adjacent exhaust that is about to close, waste as little pulse energy as possible in pressurizing other adjacent exhaust ducts, and still attain a sufficient pressure drop for the first cylinder's blowdown and scavenging phases.
One could try this scheme with a 180° twin, but it would require exhaust timings well past 200°. The ideal engine for this would be a 120° triple, like the one you've got lying around, Neil :D.

Come to think of it (I just had my first cup of coffee) we could use a rotating drum in front of the exhaust ports, parallel with the crankshaft, with passages that control which blowdown pulse is going where. That drum could double as a balance shaft.
It wouldn't be quite in accordance with KISS, but I think it would be justified if it would improve power and at the same time enable us to omit three expansion chambers.

[shnaggs]

Interesting...

I thought it would be a neat idea to use the reverse pulses from the pipe to charge the crank case when the pipe was outa sink, but I have no idea what the hot gases would do to the fresh charge in the crank case, but if the comprex works maybe this could. Now though after what fritz just said, my idea seems less fun...:weep:

[breezy]

Good article Breezy, thank you.

thanks... but... i had included quotes around the article to indicate its a quote... sadly not my thoughts , but lifted from another source... :(

[Flettner]

More info on the "drum" charger

http://www.alterego-hardware.com/images/Drum-Charger-Press-Kit-EICMA-EN.pdf

I know where you are going with this, good idea.

[Larry Wiechman]

Come to think of it (I just had my first cup of coffee) we could use a rotating drum in front of the exhaust ports, parallel with the crankshaft, with passages that control which blowdown pulse is going where. That drum could double as a balance shaft.
It wouldn't be quite in accordance with KISS, but I think it would be justified if it would improve power and at the same time enable us to omit three expansion chambers.


The Comprex Supercharger.
http://www.egr.msu.edu/mueller/projects_waverotor.htm

[Frits Overmars]

The Comprex Supercharger. http://www.egr.msu.edu/mueller/projects_waverotor.htmThat would definitely work Larry, but superchargers are forbidden in most branches of motorsport.

[Flettner]

That would definitely work Larry, but superchargers are forbidden in most branches of motorsport.

Is a Comprex supercharger an actual supercharger? It's a pulse driven system, like a chamber and they are not illegal in racing.

[Frits Overmars]

Is a Comprex supercharger an actual supercharger? It's a pulse driven system, like a chamber and they are not illegal in racing.From a gasdynamical point of view it's a pulse-driven system alright. But from a mechanical point of view it's an engine-driven contraption. There may be classes of racing where a Comprex is legal; I don't know. But from what I understand, they are generally thrown in one lot with turbos and mechanical blowers.

[Flettner]

From a gasdynamical point of view it's a pulse-driven system alright. But from a mechanical point of view it's an engine-driven contraption. There may be classes of racing where a Comprex is legal; I don't know. But from what I understand, they are generally thrown in one lot with turbos and mechanical blowers.

So if I run a mechanical rotating drum, say, in a twostroke exhaust port one to one with the engine then that would deem the engine supercharged?

[adegnes]

Controversial porting tool...
https://www.youtube.com/watch?v=sCXd0GCtzfo


https://www.youtube.com/watch?v=sCXd0GCtzfo

[wobbly]

Adegnes - So looks like the girlfriend will be getting an extra Xmas present.
For gods sake make sure to remove the file and hell,dont tell her its only been used once.

[adegnes]

Adegnes - So looks like the girlfriend will be getting an extra Xmas present.
For gods sake dont tell her its only been used once.

:laugh::laugh::laugh:

[Grumph]

So if I run a mechanical rotating drum, say, in a twostroke exhaust port one to one with the engine then that would deem the engine supercharged?

Only if the positive pressure wave side was connected to the inlet port(s).
Frits idea of blowdown direction is probably OK - but while I'm a known rules mechanic, I wouldn't swear to it's legality...
As I remember it, the FIM banned water injection into exhaust pipes as it could have reached the combustion chambers.
I'm sure someone can clarify that.

[Flettner]

Only if the positive pressure wave side was connected to the inlet port(s).


Yes Grumph, my mistake, I guess I missed that point.

[adegnes]

I have more confidence in this one!
https://www.youtube.com/watch?v=4SyTGIttCw8


https://www.youtube.com/watch?v=4SyTGIttCw8

[WilDun]

Controversial porting tool...

Way back in the day when men were men (and women were glad of it), we did it manually (by hand) and got on with the job! and we didn't need rum to do it either
We did have crude vibrators though, however they had wheels and handlebars (mainly Suzukis and Kawasakis as I recall)...........and we stuffed a lot of engines too, (lack of lubrication)!

[adegnes]

Way back in the day when men were men (and women were glad of it), we did it manually (by hand) and got on with the job! and we didn't need rum to do it either
We did have crude vibrators though, however they had wheels and handlebars (mainly Suzukis and Kawasakis as I recall)...........and we stuffed a lot of engines too through lack of lubrication!

Have you ever reshaped a set of transfers with bent files before?
Slooooow! Maybe I'm just lazy...

[WilDun]

Have you ever reshaped a set of transfers with bent files before?
Slooooow! Maybe I'm just lazy...

Yes, good things take time and can't be hurried, this could even include things like understanding my humour (read B.S.) :scratch: - sorry about that!

[adegnes]

Yes, good things take time and can't be hurried, this could even include things like understanding my humour (read B.S.) :scratch: - sorry about that!

Crap, I get it now... That's the hardest thing with a different language, picking up the jokes...

[Frits Overmars]

From a gasdynamical point of view it's a pulse-driven system alright. But from a mechanical point of view it's an engine-driven contraption. There may be classes of racing where a Comprex is legal; I don't know. But from what I understand, they are generally thrown in one lot with turbos and mechanical blowers.
So if I run a mechanical rotating drum, say, in a twostroke exhaust port one to one with the engine then that would deem the engine supercharged?Not in my book. But hey, I'm not an official anymore. Nowadays, chances are that they'll throw the book at you if you find some extra power.
And if they can't find a relevant book, they'll write a new one overnight. That's promoting technical development. And that's the main reason I resigned.


Frits idea of blowdown direction is probably OK - but while I'm a known rules mechanic, I wouldn't swear to it's legality...
As I remember it, the FIM banned water injection into exhaust pipes as it could have reached the combustion chambers.I didn't even know that water injection got banned Grumph. You sure?


Controversial porting tool... Alex, if you use tie-wraps on hand tools, the sharp cut-off ends can be annoying. But you can avoid that by using a nail-clipper instead of a pair of cutters.

Your idea reminded me of a tool I saw on www.langtuning.de
326565326566326567326568

[WilDun]

Crap, I get it now... That's the hardest thing with a different language, picking up the jokes...

Don't worry, the joke probably wasn't the best anyway!

[adegnes]

Alex, if you use tie-wraps on hand tools, the sharp cut-off ends can be annoying. But you can avoid that by using a nail-clipper instead of a pair of cutters.

Your idea reminded me of a tool I saw on www.langtuning.de
326565326566326567326568

Nice tip!
Those look to be a bit further into the refinement stages than mine currently is...

[Grumph]

I didn't even know that water injection got banned Grumph. You sure?


No. What I remember is reading in an issue of Motocourse annual that a sidecar team had been trying it with some apparent success. They stopped using it as I remember because they were told it was of dubious legality. The writeup mentioned that the FIM had now closed that loophole.

It is possible of course that when 2 strokes were dropped from the roadracing GP classes, the relevant rules were deleted too.
Our rulebook here in NZ has lost a load of rules that were there for good reasons - and when they've been dropped, no one has been advised.

[adegnes]

I visited www.langtuning.de, thinking the tool could be a cheaper alternative to other "professional" porting tools.
Guess not, 419€. It might be worth it, but that's too steep for me.

[breezy]

:laugh::laugh::laugh:

Im in tears..very funny adegnes:killingme

[adegnes]

Your idea reminded me of a tool I saw on www.langtuning.de
326565326566326567326568

Wonder what kind of "chuck mechanism" they use on those tools?
Are 3mm ID timing pulleys with set screws available? Can't find any on ebay.

[jonny quest]

How would you hold that tool? I don't know about you guys... but I hold my right angle grinder right where that belt is

[Flettner]

http://i1056.photobucket.com/albums/t380/uniflow/IMG_1262_zps8cbdc61e.jpg
http://i1056.photobucket.com/albums/t380/uniflow/IMG_1263_zpsaf4c99ae.jpg
http://i1056.photobucket.com/albums/t380/uniflow/IMG_1264_zpsa91cbe31.jpg

pinched my design :lol:
Actually I don't use this tool much now, just cast new cylinders, get the ports you want without all this fucking around with these sorts of tools. And you never get what you want anyway, it's always a compromise.
I might add, this tool was made up from crap lying around in the workshop, bit's of an old photocopier (I knew that photocopier would come in handy one day) if I remember right.

[wobbly]

Is that the new heat radiating green slime ceramic coating, you have been developing for air cooled cylinders I can see Flett.

[Flettner]

Is that the new heat radiating green slime ceramic coating, you have been developing for air cooled cylinders I can see Flett.

It's called 'organic green', just leave it outside under the lemon tree, works every time.

[jasonu]

http://i1056.photobucket.com/albums/t380/uniflow/IMG_1262_zps8cbdc61e.jpg
http://i1056.photobucket.com/albums/t380/uniflow/IMG_1263_zpsaf4c99ae.jpg
http://i1056.photobucket.com/albums/t380/uniflow/IMG_1264_zpsa91cbe31.jpg

pinched my design :lol:
Actually I don't use this tool much now, just cast new cylinders, get the ports you want without all this fucking around with these sorts of tools. And you never get what you want anyway, it's always a compromise.
I might add, this tool was made up from crap lying around in the workshop, bit's of an old photocopier (I knew that photocopier would come in handy one day) if I remember right.

Buckets at its best!!!!!

[senso]

If you have some patience you can also buy a dental 90º on ebay for 20-30€, the respective hose for a couple € and 10 boxes/50 burs for another 10-12€ and have some sweet miniature burrs do dig around ports with a lot of control.
I bought a LOT of them, and still have a couple of them lying around, and yes, they wont cut as fast as a single flute 30mm carbide burr strapped to a 5KW endmill, but they get the job done, put some 2 stroke oil into the hose, give it 1.x bars and re-oil every 30 minutes.
Those use 1.2mm shaft burrs..
Will cut nicasil coated alu and cast iron cylinders/liners with ease, and they dont vibrate a thing, and are more or less silent when compared to a dremel or any big-ish air power tool.


For 3mm burrs for dremel like cutters you have the bigger ones called contra-angle dental handpieces, more or less the same as above.

I can throw a couple links into the post so you guys get the idea.

[jonny quest]

http://p.vitalmx.com/photos/forums/2016/12/01/162454/s1200_IMG_9260.jpg

[adegnes]

If you have some patience you can also buy a dental 90º on ebay for 20-30€, the respective hose for a couple € and 10 boxes/50 burs for another 10-12€ and have some sweet miniature burrs do dig around ports with a lot of control.
I bought a LOT of them, and still have a couple of them lying around, and yes, they wont cut as fast as a single flute 30mm carbide burr strapped to a 5KW endmill, but they get the job done, put some 2 stroke oil into the hose, give it 1.x bars and re-oil every 30 minutes.
Those use 1.2mm shaft burrs..
Will cut nicasil coated alu and cast iron cylinders/liners with ease, and they dont vibrate a thing, and are more or less silent when compared to a dremel or any big-ish air power tool.


For 3mm burrs for dremel like cutters you have the bigger ones called contra-angle dental handpieces, more or less the same as above.

I can throw a couple links into the post so you guys get the idea.

I haven't tried the air-driven variety of the ebay dental tools yet, sounds like they hold up better than the electric version that just crumble in your hands...

Back on the dyno!... And the struggle continues...
https://www.youtube.com/watch?v=B9b2RutjK7U


https://www.youtube.com/watch?v=B9b2RutjK7U

[husaberg]

I haven't tried the air-driven variety of the ebay dental tools yet, sounds like they hold up better than the electric version that just crumble in your hands...

Back on the dyno!... And the struggle continues...
https://www.youtube.com/watch?v=B9b2RutjK7U

https://www.youtube.com/watch?v=B9b2RutjK7U
I enjoyed the video.
Are the engine mounts a tight fit with their bolts? and done up tight? Is the carb intake rubber soft?
Pretty sure a few had suggested 70% BF.
You can take some weight out and subsitute some alloy bungs on the light side if you have run out of area to put in Tungsten on the otherr side
You will lose crank inertia, but getting the BF factor right right be worth it for now.

[adegnes]

I enjoyed the video.
Are the engine mounts a tight fit with their bolts? and done up tight? Is the carb intake rubber soft?
Pretty sure a few had suggested 70% BF.
You can take some weight out and subsitute some alloy bungs on the light side if you have run out of area to put in Tungsten on the otherr side
You will lose crank inertia, but getting the BF factor right right be worth it for now.

Thanks!
There is a very small amount of play in the mounts cause of how they are designed. Maybe I should redo those with proper bushings before I continue, to take them out of the equation.
The carb rubber is soft.

[TZ350]

Page .... 1920

Stuffing two strokes. This is a collection of must see videos. https://www.youtube.com/channel/UCHRXYmO1vdp-Bi1-w11R7WQ



Guru, AMA tech inspector, and probably the best technical editor who ever wrote

326831326832326833326834326835326836

A great thread devoted to Kevin Cameron, worth a visit.




Enough motivation to stop procrastinating on the installation of a deto sensor. With a diameter of about 20mm at the mating side I am asking myself where to put it ideally (and where not to put it). As I run a paper gasket, I suppose somewhere on the water cooled cylinder would be nice, but there is not enough space available, except "on a stick" on one of the bolting areas for the head cover. Where du you guys put yours?


294192 294193


294223

http://www.ebay.com/itm/Knock-gauge-for-detonation-sensor-klopfsensor-NEW-/181309925670?pt=Race_Car_Parts&hash=item2a36e9e926&vxp=mtr




286854286853

Det Sensor

Follow the links back for more details.

[JanBros]

I always dyno my moped engine with locked variator, so I dyno only the engine without the influence of the vario.
then I dyno it with the vario to get the best out of the vario.

[adegnes]

I always dyno my moped engine with locked variator, so I dyno only the engine without the influence of the vario.
then I dyno it with the vario to get the best out of the vario.

That's the way to do it!
I plan on making a fixed pulley setup for the purpose.

[DaisyB]

Anyone know where I can buy a lock-out kit for the auto? Gillera Runner (125/180) and Piaggio Zip. Very time poor at the moment (not exactly cash rich either!) so no chance to make. Thanks

[Frits Overmars]

Anyone know where I can buy a lock-out kit for the auto? Gillera Runner (125/180) and Piaggio Zip. Very time poor at the moment (not exactly cash rich either!) so no chance to make. ThanksYou can try info@hvg-engineering.com. The vario lock-out kits are not mentioned on the regular hvg-engineering.com website but I know they are available.


There is a very small amount of play in the mounts cause of how they are designed. Maybe I should redo those with proper bushings before I continue, to take them out of the equation. The carb rubber is soft.If you fit a proper vario lock-out kit with a toothed belt instead of a V-belt, you will have far less transmission losses and you can temporarily tighten the engine mounts.
Did you balance your crankshaft with the inlet disk mounted?

[adegnes]

Did you balance your crankshaft with the inlet disk mounted?

You know the answer to that Frits... I've just written it's effect off as insignificant, which it probably isn't.

I'll start on the propper bushing mounts, and see what I can do about a lock out kit.

[wobbly]

I wont say that increasing the BF ( beyond where it is now ) is the fix for your vibe issues but I believe suggesting 70% is wrong.
A lightweight VERTICAL cylinder needs around 58% - going the other way a horizontal axis needs down at 35%.
A vertical Manx at 80% is a special case that just proves the point.
Every engine /chassis is a resonant system, and they each react differently, but in all cases the basic idea is to reduce the vertical bar shake symptom.
Technically your engine with its angled axis should react favorably to a BF closer to 50%,but the fuel frothing thing seems to be created by a combination
of factors not even being considered at this point.

[adegnes]

the fuel frothing thing seems to be created by a combination
of factors not even being considered at this point.

Probably.
I'm starting at the engine mounts, eliminating the slight play and introducing some dampening with rubber/plastic bushings.
Suggestions are welcome!

[dark art]

Probably.
I'm starting at the engine mounts, eliminating the slight play and introducing some dampening with rubber/plastic bushings.
Suggestions are welcome!

Bearings might work but may make the chassis vibrate much more.

I´ve seen recently a moped like that and it had a lower mounted spring to counter the engine belt pulling force, that mechanism may be guided to avoid side play and be rubber mounted for better isolation. The moped in question had only 2 mount points to hold the engine in the frame, the top one, wich pivots the engine to do the variator thing and the spring to counter force the drive belt. Is the same system as your bike?

[adegnes]

Bearings might work but may make the chassis vibrate much more.

I´ve seen recently a moped like that and it had a lower mounted spring to counter the engine belt pulling force, that mechanism may be guided to avoid side play and be rubber mounted for better isolation. The moped in question had only 2 mount points to hold the engine in the frame, the top one, wich pivots the engine to do the variator thing and the spring to counter force the drive belt. Is the same system as your bike?

Bearings could work!

That's how the stock setup works on these bikes.
My "parallelogram" mount has two mounting points and the engine is moving in a more linear fashion. This has the advantage of more rigidity, and no need for flexible parts/ball joint in the pipe.

[richban]

Well the 300 used to look like this 3 days ago. Now its in a sad state a little like me. Big big crash. On a plus they were all going very well. With Glen securing pole, a win and a lap record. Race 2 was stopped due to me going over the bars.

326621

326622

[FastFred]

.

An interesting read:- http://forums.everything2stroke.com/threads/49513-How-It-s-Done-Projects-around-the-Shop/page45

[mr bucketracer]

Well the 300 used to look like this 3 days ago. Now its in a sad state a little like me. Big big crash. On a plus they were all going very well. With Glen securing pole, a win and a lap record. Race 2 was stopped due to me going over the bars.

326621

326622how good are the new pipes on bike? Looks like you finished race 2 ..what's happening?

[adegnes]

My take on the belt(o-ring) style 90° porting tool.


https://www.youtube.com/watch?v=W6V5Piz_Uz8

[wobbly]

Rich - shame I couldnt have been at Taupo to see the 2Ts kick arse, but I was ( am ) flat out on Dennis's new one.
A friend saw your crash, and told me you were not a well boy with a broken pelvis.
Shit man thats a major, so a heart felt " get well soon " from me.
The bikes an easy fix, a pelvis break aint.
WTF happened.

[Drew]

Rich - shame I couldnt have been at Taupo to see the 2Ts kick arse, but I was ( am ) flat out on Dennis's new one.
A friend saw your crash, and told me you were not a well boy with a broken pelvis.
Shit man thats a major, so a heart felt " get well soon " from me.
The bikes an easy fix, a pelvis break aint.
WTF happened.

Nah, it's just his back.

[timg]

Well the 300 used to look like this 3 days ago. Now its in a sad state a little like me. Big big crash. On a plus they were all going very well. With Glen securing pole, a win and a lap record. Race 2 was stopped due to me going over the bars.

326621

326622 Awww bugger :( All the best with recovery mate

[Flettner]

My take on the belt(o-ring) style 90° porting tool.


https://www.youtube.com/watch?v=W6V5Piz_Uz8

Adegnes, I do like your videos, but Rum? Perhaps a little E85 might do the trick.:laugh:

[husaberg]

My take on the belt(o-ring) style 90° porting tool.

https://www.youtube.com/watch?v=W6V5Piz_Uz8

Adegnes you might find it less cumbersome on smaller cylinders if you you a flexidrive on the dremel hung from a hook.
Or you could make a flexidrive out of the old speedo cable.
i also seen these, they seem cheap enough.
Slightly more ergonomic as well. Not as coll as making your own of course.
thi =s would also be better driven from a flexdrive.
http://images.4cheapink.com/ebay/images/AMA/project1_PPNLPG110/B000KICSGQ_2.jpg
http://www.ebay.co.uk/itm/Milescraft-1302-Drive90-Right-Angle-Drilling-and-Driving-Power-Drill-Sale-/332000547726?hash=item4d4cc6538e:g:go4AAOSwNRdYATL 3

[richban]

Rich - shame I couldnt have been at Taupo to see the 2Ts kick arse, but I was ( am ) flat out on Dennis's new one.
A friend saw your crash, and told me you were not a well boy with a broken pelvis.
Shit man thats a major, so a heart felt " get well soon " from me.
The bikes an easy fix, a pelvis break aint.
WTF happened.


Cheers Wob. Apparently there was all sort of theories on my injuries. I have a couple of small stable fractures in my upper back and thats about it. I will fine. Even today i am moving more freely. It was a very fast and brutal crash. Over the bars at around 140 /150 kpm. I can tell you now if you want to save some weight on Dennis's bike you can run a single 320 rotor. Enough power to flip the bike. We have all switched to single rotor calliper setup. I have not seen the bike properly yet its still in the trailer. I will post a before and after pic at some point.

[adegnes]

Adegnes, I do like your videos, but Rum? Perhaps a little E85 might do the trick.:laugh:
:laugh:



Adegnes you might find it less cumbersome on smaller cylinders if you you a flexidrive on the dremel hung from a hook.
Or you could make a flexidrive out of the old speedo cable.
i also seen these, they seem cheap enough.
Slightly more ergonomic as well. Not as coll as making your own of course.
thi =s would also be better driven from a flexdrive.
http://images.4cheapink.com/ebay/images/AMA/project1_PPNLPG110/B000KICSGQ_2.jpg
http://www.ebay.co.uk/itm/Milescraft-1302-Drive90-Right-Angle-Drilling-and-Driving-Power-Drill-Sale-/332000547726?hash=item4d4cc6538e:g:go4AAOSwNRdYATL 3

Good ideas!
I've been playing with the idea of a thin/flexible/strong enough flex cable that could be connected directly to the porting head.
Don't know if such a thing exists.

[wobbly]

I am using twin small 255mm discs, the wet setup from Aoyamas 250GP title bike, be interested to see what a 320mm and caliper weight is.
The rotational inertia would be greater I would imagine, but the race 1098 one piece calipers are heavy as - just cant afford the smaller 250GP versions.

[Sketchy_Racer]

I am using twin small 255mm discs, the wet setup from Aoyamas 250GP title bike, be interested to see what a 320mm and caliper weight is.
The rotational inertia would be greater I would imagine, but the race 1098 one piece calipers are heavy as - just cant afford the smaller 250GP versions.

Back of the envelope calc would suggest that the 255mm disks will have a advantage with a lower MOI than the single disk but the single disk setup will have less un-sprung weight.

I'm genuinely impressed with the performance of the single disk, my only concern is over heating it at Wanganui races....

Anyway, here's a wank shot of the NSR300 doing it's thing onto the front straight of Taupo, by far the best i've ever had it running!

326637

[Drew]

Back of the envelope calc would suggest that the 255mm disks will have a advantage with a lower MOI than the single disk but the single disk setup will have less un-sprung weight.

I'm genuinely impressed with the performance of the single disk, my only concern is over heating it at Wanganui races....

I ran a single 320mm rotor on an FZR 750 race bike. It ate the disk, but it took three meetings at Manfeild before that. I shouldnt think you'll have an issue on the 250 at all.

[TZ350]

Well the 300 used to look like this 3 days ago. Now its in a sad state a little like me. Big big crash. On a plus they were all going very well. With Glen securing pole, a win and a lap record. Race 2 was stopped due to me going over the bars.

Very Sorry to hear you have suffered a few injuries, get well soon. But glad to hear the bikes are going well, I expect the bent one will straiten up Ok, I have a spare MC21 frame and swing arm, yours if you need it.

[richban]

Very Sorry to hear you have suffered a few injuries, get well soon. But glad to hear the bikes are going well, I expect the bent one will straiten up Ok, I have a spare MC21 frame and swing arm, yours if you need it.

Cheers Rob. I was put off racing for a day or so. Now I just want to pull the bike out of the trailer and start fixing it. I also have a spare frame and swinger. Thanks for the offer. It might be baby steps going racing again. I will work on getting the 50 sorted first.

[F5 Dave]

Yeah don't make decisions in haste.
There's always the 50. You can't possibly hurt yerself on that.

[husaberg]

:laugh:




Good ideas!
I've been playing with the idea of a thin/flexible/strong enough flex cable that could be connected directly to the porting head.
Don't know if such a thing exists.
It turns out generic multi tools stuff is pretty cheap
http://www.ebay.co.uk/itm/575-Right-Angle-Drive-Attachment-Converter-for-Dremel-High-Speed-Rotary-Tools-/182108491993
326649
http://www.ebay.co.uk/itm/Brand-New-Flexible-Drill-Drive-Shaft-1070mm-Flexi-Rotary-Tool-Hobby-Tool-/131731684667
326648
http://lumberjocks.com/assets/pictures/projects/106972-438x.jpg

[adegnes]

It turns out generic multi tools stuff is pretty cheap
http://www.ebay.co.uk/itm/575-Right-Angle-Drive-Attachment-Converter-for-Dremel-High-Speed-Rotary-Tools-/182108491993
326649
http://www.ebay.co.uk/itm/Brand-New-Flexible-Drill-Drive-Shaft-1070mm-Flexi-Rotary-Tool-Hobby-Tool-/131731684667
326648
http://lumberjocks.com/assets/pictures/projects/106972-438x.jpg

I'm actually using that black flex shaft you posted.
Hmm, maybe that bulky 90° dremel attachment could be modified to fit in small cylinders, think I'll order one.

What I was thinking about was something small enough to be fed through the exhaus or up a transfer and then connected to a "burr on a stick". Maybe some RC flex drive stuff can be used.

[F5 Dave]

Look at the pictures in the eBaylink compared to human hands. They would be just fine for a 500 but a bit compromised in a 250.

[speedpro]

I've got a Dremel right angle attachment and you cannot get into a MB100 cylinder with it. Nice bit of gear though, just of no use.

[philou]

How to tune right angle Dremel

http://img11.hostingpics.net/pics/695788dremel28129.jpg

http://img4.hostingpics.net/pics/561727Photo051.jpg

http://www.mobcustom.com/forum/general-(50-a-boites)/modification-renvoie-d'angle-dremel/

[TZ350]

... here's a wank shot of the NSR300 doing it's thing onto the front straight of Taupo, by far the best i've ever had it running!

326637

I have always dreamed of being able to do that with my Bucket, great shot.

[adegnes]

How to tune right angle Dremel

http://img11.hostingpics.net/pics/695788dremel28129.jpg

http://img4.hostingpics.net/pics/561727Photo051.jpg

http://www.mobcustom.com/forum/general-(50-a-boites)/modification-renvoie-d'angle-dremel/

Nice mod! Love it!

[TZ350]

Cheers Rob. I was put off racing for a day or so. .... I will work on getting the 50 sorted first.


Yeah don't make decisions in haste. There's always the 50. You can't possibly hurt yerself on that.

When I rode bigger bikes I never thought I could be frightened by a 50 but now they actually seem a challenge and even a little frightening ...... :laugh: . I very much want a 50 of my own.

[F5 Dave]

Certainly taught me about what to order from the hospital menu and what to avoid.

[Grumph]

Certainly taught me about what to order from the hospital menu and what to avoid.

See...Bucket racing can teach you useful skills. That knowledge will be very handy as you age disgracefully.

[Michael Moore]

In re alternate charging systems:

[tjbw]

In re alternate charging systems:

Another nice Maico prototype, first time I've seen the internals of this one. Thanks Michael, BTW this could also be posted in the "oddball engines .." topic.

[WilDun]

Another nice Maico prototype, Thanks Michael, BTW this could also be posted in the "oddball engines .." topic

I see you did get it moved to the 'Oddball thread' TJBW.

[philou]

I want to convert the hrc needle reference to reference keihin

There exists a table or means of conversion ?

Needle HRC 16203-NX4-780 marking 1268/3466/2351

[husaberg]

I want to convert the hrc needle reference to reference keihin

There exists a table or means of conversion ?

Needle HRC 16203-NX4-780 marking 1268/3466/2351

I would say to have to measure them out. The Kehin numbering system is based an angles and widths and certain points along its width.
326688326689
The problem is though these carbs are ketting older and as the Jet Needle wears the needles need to be made thicker to acomidate this wear.

[G Jones]

the problem is the local machinist does mostly automotive stuff and says he cant do a radius in the head band. either he doesn't know how or his machine isn't capable. so for now I wont have a radius in the head band until I can send the head off to someone else. heres what I have since the last bit of cutting.
I may have posted this before - can't remember - whether it's necessary to follow piston radius or not for squish - it's what I wanted to do with our TZ350 - don't have easy access to cnc - so found a way to get it done with what i did have available...
http://maplesigns.co.uk/photogallery/albums/userpics/10002/DSC02129.JPG

http://maplesigns.co.uk/photogallery/albums/userpics/10002/DSC02136.JPG

http://maplesigns.co.uk/photogallery/albums/userpics/10002/DSC02134.JPG

[OopsClunkThud]

You can also cut a hemisphere on a knee mill with the head set at an angle. The combination of the angle and cutter determine the radius of the hemisphere. The diameter of the cutter equals the chord length.

http://members.modernvespa.net/oopsclunkthud/uploads/img_1626_88483.png
http://members.modernvespa.net/oopsclunkthud/uploads/img_1629_11374.png

[jasonu]

I may have posted this before - can't remember - whether it's necessary to follow piston radius or not for squish - it's what I wanted to do with our TZ350 - don't have easy access to cnc - so found a way to get it done with what i did have available...
http://maplesigns.co.uk/photogallery/albums/userpics/10002/DSC02129.JPG

http://maplesigns.co.uk/photogallery/albums/userpics/10002/DSC02136.JPG

http://maplesigns.co.uk/photogallery/albums/userpics/10002/DSC02134.JPG

I like that method. Very 'bucket racing'.
To do mine I hand ground a piece of my (at the time) employers carbide (or was it tool steel I don't remember) into the shape of the dome that I thought was correct and used it to cut the shape. I then used carborundum paper to sand it smooth then brasso to do the final polish. Right or wrong it seamed to work OK.

[G Jones]

I like that method. Very 'bucket racing'.
To do mine I hand ground a piece of my (at the time) employers carbide (or was it tool steel I don't remember) into the shape of the dome that I thought was correct and used it to cut the shape. I then used carborundum paper to sand it smooth then brasso to do the final polish. Right or wrong it seamed to work OK.Always more than one way to "skin a cat" :cool:
I looked at and thought about this for quite a time - then realized I'd got the ideal radius cutting tool in the rotary table - looks a bit cack but does the job very well - more important to get it repeatable with the twin engine - you want both to be identical... - you wouldn't want to see the tooling I made to put circlip grooves in RD250 cases to use for TZ350...:rolleyes:

[adegnes]

The forming tool way is nice, cause then your not restricted to a hemisphere shape!

If anyone's curious to know what's going on with the Spx, I've ordered some urethane resin and will be making new engine mounts with cast in bushings. Crossing fingers for that to soak up enough vibration to keep my carb happy. Video coming.

[adegnes]

More from your favorite entertainer!


https://www.youtube.com/watch?v=WtDHbYNiGXs

[Frits Overmars]

More from your favorite entertainer!Thanks for the credits Alex. You'll make us famous yet :2thumbsup.

[mr bucketracer]

More from your favorite entertainer!


https://www.youtube.com/watch?v=WtDHbYNiGXsdid you cheak the otherside of the crank as it looked like it was going up and down in video , hard to see

[wobbly]

Only one small step from famous to legendary Frits.

[adegnes]

Thanks for the credits Alex. You'll make us famous yet :2thumbsup.

:2thumbsup:


did you cheak the otherside of the crank as it looked like it was going up and down in video , hard to see

I'll have to recheck it. Thought that if one side is running true - both sides are good. If the shafts aren't bent(could be the case here).

[wobbly]

Never assume - its just an error just waiting to be revealed.
The pin can be " cocked " in a web hole, or both ,especially with a crank that moves as easily as that one does.
If it moves like that when applying hardly any force, imagine whats going to happen at 14,000 rpm.
Only fix for a shitter like that is to Tig the pins after truing,special stepped pins, or bin it.
The only way to ensure pins, or webs arent " cocked " when pressed together, is to use a die set that keeps all the faces parallel.

[adegnes]

Never assume - its just an error just waiting to be revealed.
The pin can be " cocked " in a web hole, or both ,especially with a crank that moves as easily as that one does.
If it moves like that when applying hardly any force, imagine whats going to happen at 14,000 rpm.
Only fix for a shitter like that is to Tig the pins after truing,special stepped pins, or bin it.
The only way to ensure pins, or webs arent " cocked " when pressed together, is to use a die set that keeps all the faces parallel.

True true.
I've told the owner of the crank that I highly recommend he get a new one. I mean I could probably bend it out of true with just my hands.

[F5 Dave]

Working on the principle of the stopped clock that's dead accurate twice a day: the bendy crank is probably true , we'll, sometimes. . . Is 'often' acceptable?;)

[jonny quest]

That could be your vibration problems. Crank isn't true

[adegnes]

That could be your vibration problems. Crank isn't true

Hmm... Could be. I've indicated both sides of the Spx crank though, within 0.01mm

But just to get this straight:cool:, if I measure no runout on one side, and the shafts are not bent, is it possible for the other side to be out of true? It's relative and all that.
When I'm indicating one side and I can't get it true I assume that it's cocked on the pin, hit one side to see if it gets better/worse and work from there. Usually does the trick.

[wobbly]

Yes it easily possible to have one side read zero, and the other wave about at 0.03 - as you say if the pin isnt true
in the crank wheel bore - I see this all the time.
Have you checked the crank, now its been installed and run.
Could be miles out if the press fit isnt sufficient.

[adegnes]

Yes it easily possible to have one side read zero, and the other wave about at 0.03 - as you say if the pin isnt true
in the crank wheel bore - I see this all the time.
Have you checked the crank, now its been installed and run.
Could be miles out if the press fit isnt sufficient.

The bushing urethane for my new engine mounts arrived today so I'll make those first and see if it changes anything. My current setup is metal on metal with no bushings, slightly loose so it doesn't bind up - just a test setup really.
If the problem is still there I'll tear it down and recheck the crank. The pressfit seemed fine tho, nothing like the crank in my last video.

Maybe I've made a too loose "slip fit" on my main bearings? I noticed they were easier to push onto the crank now than last time I had it apart.

[adegnes]

I rechecked the crank from the video, sure enough the other side was running out big time... Doesn't matter really, cause I also discovered that I can easily move the webs with just my hands.

The thing is, all the crankshafts I've checked and trued before has been "just to be sure" cases, never done one that's been taken apart and (carelessly) pressed together, nor experienced the really cocked pin scenario.(until now)

I'm getting a second dial indicator, to see what's going on with both sides simultaneously, and start working up my cocked pin/web knowledge.

[Larry Wiechman]

I rebuilt a small Suzuki crank that was impossible to true.

The crank halves each had a different stroke.:brick:

[adegnes]

I rebuilt a small Suzuki crank that was impossible to true.

The crank halves each had a different stroke.:brick:

:laugh::laugh::laugh:

[jasonu]

I rebuilt a small Suzuki crank that was impossible to true.

The crank halves each had a different stroke.:brick:

A dual stroke crank, you could enter several different classes with that one.....:niceone:

[Ocean1]

A dual stroke crank, you could enter several different classes with that one.....:niceone:

A genuine two stroke, no less...

[adegnes]

A genuine two stroke, no less...

Genius! Why can't I come up with stuff like this!?

[Frits Overmars]

Genius! Why can't I come up with stuff like this!?Maybe it's the rum? Naah....

[adegnes]

Maybe it's the rum? Naah....

Of course, that's the reason, not enough rum!

[wobbly]

Yep, been there as well.
Thats why having two dial gauges is the way to go.
If you set them up on the same axle and they both rise and fall in line with the big end, that means the stroke length
is different, side to side.
But if the inner dial is still and the outer is up and down,or vise versa then the pin is cocked in the press fit bore.
I have a pile of wheels for YPVS/Banshee, and had to get them all checked on a CNC measuring machine - the stroke length varied
up to 0.036 mm, so now I can match them in pairs.

I agree about the Rum as well - ditch that for some Scotch.Its made from grain so is practically muesli, a health food.

[adegnes]

I agree about the Rum as well - ditch that for some Scotch.Its made from grain so is practically muesli, a health food.

Good point! :laugh: :laugh:

Started on the new engine mounts with cast-in urethane bushings.


https://www.youtube.com/watch?v=j-GOXoaspyU

[breezy]

Adegnes, will the stiffness of the europhane bush, as opposed to a vulcanised rubber type bush, maybe still pose vibration problems.:sherlock:?

[adegnes]

Adegnes, will the stiffness of the europhane bush, as opposed to a vulcanised rubber type bush, maybe still pose vibration problems.:sherlock:?

That's a possibility, the stuff I've used is pretty hard. We'll see how it goes.
I fear that going too soft with the mounts could introduce enough flex in the system to screw up pulley alignment and flip/derail the belt. It doesn't take much.

[husaberg]

Adegnes, will the stiffness of the europhane bush, as opposed to a vulcanised rubber type bush, maybe still pose vibration problems.:sherlock:?


That's a possibility, the stuff I've used is pretty hard. We'll see how it goes.
I fear that going too soft with the mounts could introduce enough flex in the system to screw up pulley alignment and flip/derail the belt. It doesn't take much.

What's the shore rating of the resin? 60? 80? shore A.

[adegnes]

What's the shore rating of the resin? 60? 80? shore A.

It's 75D, harder than I expected...

Upcoming project, unconventional Derbi build, a test bench for trying out new ideas


https://www.youtube.com/watch?v=RkIttVMREHc

[husaberg]

It's 75D, harder than I expected...

Upcoming project, unconventional Derbi build, a test bench for trying out new ideas

https://www.youtube.com/watch?v=RkIttVMREHc

That might be a little to stiff?
Google informs me engine vibration Mounts are generally 60-70A. (I checked)

https://www.youtube.com/watch?v=Q6jn223_1Mw
then again it should be better than before anyway:D

[adegnes]

That might be a little to stiff?
Google informs me engine vibration Mounts are generally 60-70A. (I checked)

https://www.youtube.com/watch?v=Q6jn223_1Mw
then again it should be better than before anyway:D

Thanks for the info and video! I just saw "75" and didn't know about the different scales(should have looked that up...) No wonder it was surprisingly hard when cured...
I ordered some 85a after squeezing on some skateboard wheels I felt had the stiffness I need.

[husaberg]

Thanks for the info and video! I just saw "75" and didn't know about the different scales(should have looked that up...) No wonder it was surprisingly hard when cured...
I ordered some 85a after squeezing on some skateboard wheels I felt had the stiffness I need.

You could always machine some out of skateboard wheels or what not.

[adegnes]

You could always machine some out of skateboard wheels or what not.

Yep could do that, or just buy skateboard truck bushings, or plain round stock, or even ready made silent blocks.
I've never done much casting with plastics, and wanted to learn more about it.
On the subject, I plan for the wrist pins to be able to rotate in the urethane while the engine moves, will this cause problems with rapid wear you think? Maybe better to cast in bronze bushings or similar for the pins ro ride in.

And off the subject, I'm seriously considering getting a 3d printer kit and give "lost pla" casting of cylinders a go.

[peewee]

Currently the fastest engines use the 2 petal setup as the extra dividers for 3 or 4 per side create more turbulence ( or double that in a VeeForce )
Extending the dividers both horizontally and vertically with airfoil leading edges also decreases the flow disruption caused
when the air suddenly hits a short support close to the petal.
The 2 wide petals will be alot stiffer, so will have to be thinner ( or waisted at the clamp face ) to achieve the same lift due to case depression assisted by intake column tuning.
I have seen tests adding vertical dividers to an older VeeForce ( that already has the horizontal wing shape ) and this made better power.
Newer ( higher flowing ) versions of the VeeForce have the vertical dividers now as well.

since i removed some cage fingers, I was using a 2 wide petal glass fiber at .53mm thick but I made some calls and I think I can get some 2 wide petal carbon fiber low tension, probly .40mm thick im guessing. think these would be worth trying ? maybe even add a small stiffener petal on top if needed

[wobbly]

There is lots of power to be had using the thinnest petals you can, with backup stiffeners.
Also biasing the flow to the top set is the go.
The TM KZ10C uses the same petals top and bottom
But double backups on the bottom and a single on on top,upside down ie curved upward.
The best setup in a SKUSA CR125 is a single bottom blade with double backups, the top reed is 3 petals with a spacer under a single
short backup.

[ken seeber]

And off the subject, I'm seriously considering getting a 3d printer kit and give "lost pla" casting of cylinders a go.

Alex,
Now you’re talking. Feel free to post your casting experiences in the Bucket Foundry. Also feel free to bring the RUM (Rudimentary Undigestable Matter). :clap:
PS: Don’t forget your safety glasses when splashing hot metal.

[F5 Dave]

And special Foundry shorts.

[husaberg]

Yep could do that, or just buy skateboard truck bushings, or plain round stock, or even ready made silent blocks.
I've never done much casting with plastics, and wanted to learn more about it.
On the subject, I plan for the wrist pins to be able to rotate in the urethane while the engine moves, will this cause problems with rapid wear you think? Maybe better to cast in bronze bushings or similar for the pins ro ride in.

And off the subject, I'm seriously considering getting a 3d printer kit and give "lost pla" casting of cylinders a go.

i think you should be fine, Poly suspension bushes do the same job but under far greater loads without the need for sleeves, just a tiny bit of lube to stop the squeeks.

[Ocean1]

On the subject, I plan for the wrist pins to be able to rotate in the urethane while the engine moves, will this cause problems with rapid wear you think? Maybe better to cast in bronze bushings or similar for the pins ro ride in.

Under normal circumstances urethane wears very well, better than any bush you might build in.

Doesn't like heat though.

[adegnes]

Alex,
Now you’re talking. Feel free to post your casting experiences in the Bucket Foundry. Also feel free to bring the RUM (Rudimentary Undigestable Matter). :clap:
PS: Don’t forget your safety glasses when splashing hot metal.
I will, and of course I'll bring the rum!



And special Foundry shorts.

:killingme


i think you should be fine, Poly suspension bushes do the same job but under far greater loads without the need for sleeves, just a tiny bit of lube to stop the squeeks.

Great!

[marsheng]

Data loggers are great but often you get the data too late especially in a 2 stroke. When you get back to the pits, you can see that the CHT rose every lap by XX degrees and was at max just before the back wheel locked up. I've made a CHT/EGT analog display that gives real time data in an easy to see instrument. It is small and so can be fitted easily to any bike or kart.

What I would like is any one with real data from CHTs and EGTs from specific engines so I can get an idea on the range of temperatures that are actually being measured.

About the only CHTs I can find is for Rotax Aircraft engines and that is between 180 and 220 deg C.
I'm guessing that most air cooled engines are similar, hence the posting.

Water temperatures are around 60 deg c, but does anyone have an idea on what the plug temperature would be. I'm sure the plug temperature rises more quickly than the water temp does.

I'm hoping that my monitoring EGT and CHT live, deto and seizing can be avoided.

So if you have some actual reliable data, can you post it please with the motor it was measured on.

Once I have data, I'll be selling the units.

[jfn2]

wobbly:
Do you have any pics of the reed set-ups your talking about?

[OopsClunkThud]

About the only CHTs I can find is for Rotax Aircraft engines and that is between 180 and 220 deg C.
I'm guessing that most air cooled engines are similar, hence the posting.

I've run CHT/EGT on 5 different bikes (all air cooled, 50-160cc) and use 175-225C as the safe range for CHT. This was for endurance rides where the temp is held for long periods of time. I find CHT tends to be highest at lower RPM and downshifting will bring it back in line.

[wobbly]

Temp range for the under plug depends alot on how good the cooling of the insert is ( in water cooled ) and how good
the head design and material type is ( in air cooled ).
The CHT range is around 160 to 260*C
EGT is usually in the 580 to 680*C
But as far as seizure prevention is concerned the important deal is that the instant deto begins, the EGT delta rise slows and the CHT goes mental.
As long as they are both rising together all is OK - and NO,the egt dropping as the CHT rising does NOT mean its rich.
Once serious deto is occurring the EGT will drop quickly, whilst the CHT goes up seriously.
This is due to all the energy of combustion being consumed in creating the deto radicals, that eat away the piston and head in the squish band.

[wobbly]

Here is the TM parts page.
There is a newer reed petal set, that makes better power with both bottom backups pointing inward
and the single top one pointing away from the petal.

[peewee]

In a sim the power continues to rise as the reeds are made thinner ( from being too thick ) , due to the petals resonant frequency coinciding with the forcing frequency of the intake tract.
BUT,as you drop the resonant rpm you are also effectively increasing the lift and petal open duration.
This very quickly runs into trouble at peak power and beyond,as the instant the petals hit a stop, or are not stiff enough to exhibit controlled drop back
onto the seat,they go completely spastic.
Easily seen in the sim as wildly varying tip lift ( and a big power drop ) with each sim iteration in turn.
One trace run will show a good result, the next trace the lift is all over the place.
Add a couple of 1/10 of a mm to the petal thickness and the resonant rpm will rise a few hundred, and the effect goes away in the top end.
This is exactly what the sim is for - to point you in the right direction with what to be trying on the dyno.
IMHO there are way to many variables involved to even begin to formulate a workable rule of thumb for reeds, as in reality, suck it and see is the only way.

I have just completed a huge number of sims for the KZ10 with all manner of different reed blocks, the only way to get a meaningful result was to set the petal thickness for every block
such that the 1st harmonic rpm was 10,000 with engines natural peak power at 13200 ( as in reality ).
This then shows the real effect of the reed block geometry on the power - not the differences due to the varying petal thickness - as this is easily changed during the subsequent dyno confirmation process.

theres no rule of thumb for the stiffeners ? I see some are smaller rectangles on top of the main rectangle petals. some were triangle shape. what about the thickness and material in relation to the main petals. has to be some kind of approximation to get started in the right direction :laugh:

[jfn2]

First, what is magmalyte?
I see that the cage itself has a rounded nose. What would be the cage angle and why is the nose rounded and not more v-shaped? Does this have something to do with the shaping on the inside?

Wobbly:
With turning of the backups on the bottom and turning around the backup on top be in line with trying to get the intake charge to favor the top set of reeds. Does this not also change the stiffness of the top set of reeds? Couldn't you just change to a thinner material on the top? Do you have a pic of the reed and cage assembled? Thanks.

[marsheng]

I've run CHT/EGT on 5 different bikes (all air cooled, 50-160cc) and use 175-225C as the safe range for CHT. This was for endurance rides where the temp is held for long periods of time. I find CHT tends to be highest at lower RPM and downshifting will bring it back in line.

Thanks very much. Useful data for me.

I wonder if it is lean at low RPM and a downshift brings in a lot more cooling air and gas ?

[marsheng]

Temp range for the under plug depends alot on how good the cooling of the insert is ( in water cooled ) and how good
the head design and material type is ( in air cooled ).
The CHT range is around 160 to 260*C


is this for both air and water cooled motors?

[Frits Overmars]

I wonder if it is lean at low RPM and a downshift brings in a lot more cooling air and gas ?Air and gas are often brought in with the intend to make a fire...

[cotswold]

My old 50 the NSR one,
It's onto it's 3rd owner now and at the weekend it seized, I was asked to have a quick look as he wanted to get back out on it. I took the top off and there was a ring of melted ally around the outside of the piston and the combustion area of the head had been hammered into the squish area.
I should have taken photo's
when I was checking over the head I found the plug was hand tight, could this have been a case of very lean mixture or has anyone got another idea?
I will ask him to take a couple of photo's if anyone is interested

[wobbly]

Yes the whole idea of differing reeds and backups to to bias the flow into the upper ports.
The KZ10 reed block isnt rounded - thats just an artists impression, the angle is 58* and its a normal exit shape.
There are various aero blade inserts made for these, and the biggest/longest horizontal foil section insert works best.
As I said previously you cant simply keep on making the top petal thinner, as you quickly end up with the reeds natural frequency
making it loose control at high rpm and it " flutters " uncontrollably.
I saw this on the flow bench with a set of stock CR125 petals, they have no backups and as soon as the lift/length ratio approaches 1/3
the petals bounce around in a rhythmic pattern - the best petals on the dyno,with backups, went to full lift and sat there.
Notice that the backups only contact the outer sides of the main petals, this seems to be designed to prevent fretting on the outer corners
but obviously they affect the stiffness of the main petals as well.
Maybe it also reduces the turbulent exit flow spilling over the sides of the ports, and forces more flow down the middle.

Re the CHT numbers - yes the range is for water cooled at the bottom end and air cooled up over 200.
Yamaha KT100 engines had a change from sand cast to die cast at some stage, and the different material/ casting technique ( exact same head shape ) caused a drop in CHT
from 230C to 170C.

[Haufen]

That may not break the pocelain but it can very well cause an different problem. An open ended wrench bears on just two points of the hexagon and as the spark plug body is relatively thin-walled, you'll risk pushing the hexagon out of round, causing leakage at the top seal between the hexagon and the porcelain.



Thanks, I will keep that in mind. Although a quick inspection of the broken plugs revealed that all of them were fine in the transition area between the hexagon and the porcelain.
I will now carefully mount the new plug with the proper tooling and report back when I have new findings.


Okay, so I can report back that I can now repeatably destroy NGK R7376-10 plugs by running just a tad too lean when pushing to the limits on the dyno in a high bmep application, due to causing "funny" combustion pehenomena. The toolings used to tighten the plug had no influence on the result, unfortunately.

Enough motivation to stop procrastinating on the installation of a deto sensor. With a diameter of about 20mm at the mating side I am asking myself where to put it ideally (and where not to put it). As I run a paper gasket, I suppose somewhere on the water cooled cylinder would be nice, but there is not enough space available, except "on a stick" on one of the bolting areas for the head cover. Where du you guys put yours?

[marsheng]

Air and gas are often brought in with the intend to make a fire...

Oh yes it does but here is a lesson I learned the other day.

I have a very heavy dyno drum. 700 KG

In running in a motor, I reved the bike up 10K and then closed the throttle. As it slowly coasted down to an idle, the exhaust pipe began to glow red hot. I opened the throttle and the pipes went from red to black again. I repeated the process to confirm and it replicated the result.

I understand that a lean mixture burns slower and the gasses can still be burning when the exhaust valve opens, hence the exhaust pipes get really hot. So in this case, more air and fuel actually cooled the exhaust.

Cheers Wallace

[Frits Overmars]

Okay, so I can report back that I can now repeatably destroy NGK R7376-10 plugs by running just a tad too lean when pushing to the limits on the dyno in a high bmep application, due to causing "funny" combustion pehenomena.That's not nice to hear, but good to know. There seem to be two kinds of NGK R7376-10 plugs on the market: one is expensive and reliable; the other is neither.
How much was your version?
And of course you made me curious about your combustion phenomena. Care to elaborate?


Enough motivation to stop procrastinating on the installation of a deto sensor. With a diameter of about 20mm at the mating side I am asking myself where to put it ideally (and where not to put it). As I run a paper gasket, I suppose somewhere on the water cooled cylinder would be nice, but there is not enough space available, except "on a stick" on one of the bolting areas for the head cover. Where du you guys put yours?As you say: on a stick, like on the RSA-picture below. But with limitations: the sensor should be pulled directly onto the head; no nut in between.
327044


In running in a motor, I reved the bike up 10K and then closed the throttle. As it slowly coasted down to an idle, the exhaust pipe began to glow red hot. I opened the throttle and the pipes went from red to black again. I repeated the process to confirm and it replicated the result. I understand that a lean mixture burns slower and the gasses can still be burning when the exhaust valve opens, hence the exhaust pipes get really hot. So in this case, more air and fuel actually cooled the exhaust. I see what you mean Wallace. In an engine running at 10.000 rpm with a closed throttle there should be no combustion at all. In your case the mixture, although very lean, must still have been rich enough to be igniteable. That's not good. And apparently combustion is so slow that the mixture is still burning when the exhaust opens. That's bad. If it makes the exhaust pipe glow red hod, think what it will do to the exhaust valve. Wait a minute: exhaust valve? Carry on; you'll be fine :devil2:.

[Haufen]

That's not nice to hear, but good to know. There seem to be two kinds of NGK R7376-10 plugs on the market: one is expensive and reliable; the other is neither.
How much was your version?
And of course you made me curious about your combustion phenomena. Care to elaborate?

As you say: on a stick, like on the RSA-picture below. But with limitations: the sensor should be pulled directly onto the head; no nut in between.
327044

Some time ago someone (you?) posted the part number of the expensive kind - and I can confirm that I have recently destroyed the 4th piece of the expensive kind.
(This then led me into conducting a plug test in which the standard NGK BR10ES gapped @ 0,45mm surprisingly matched the 7376. No surprises from Brisk, Bosch and other fancy NGK stuff, but mostly a tad lower or not comparable due to different combustion chamber volume and / or electrode position)

I would love to approach this combustion phenomena with fully indicated engine and a couple of combustion chambers, as I am sure one could learn a lot from it in a short period of time. But for this hobby application I have to do it the oldschool way, I suppose. I will check if I can find a recording of the engine sound. As the engine approaches maximum power or shortly thereafter, there may be a kind of "poof" if it is slightly too lean, and if its a bit leaner there is no "poof" and the engine just dies as if the kill switch would have been activated. If I do not lean the engine off with the e-PJ, nothing happens (except for that lost horse and a bit of powerband). As this is caused by a too lean condition, I suspect it to be pre-ignition and wrongly timed, as it also kills all the resonance in the engine. Fortunately, besides from dead spark plugs, the rest of the engine seems to be fine.

Unfortunately my head cover and the combustion chamber do not share a bolt position as in the RSA. So I could only get the signal from the cylinder, not directly from the head insert. Do you expect this to cause issues or significantly weaken or change the signal?

[Martin1981]

hi wobbly, i sent you a PM.

[Frits Overmars]

Unfortunately my head cover and the combustion chamber do not share a bolt position as in the RSA. So I could only get the signal from the cylinder, not directly from the head insert. Do you expect this to cause issues or significantly weaken or change the signal?I can't say without knowing exactly how you are going to mount the sensor. I guess you will just have to find a place in direct solid contact with the combustion chamber, and even then it will be a matter of trial and error.
All parts of an engine vibrate with some frequency, with some amplitude and in one plane or another, and these vibrations may attenuate the detonation-induced vibration to some extent. Conversely, parts resonating in their own root frequency may fool the sensor into reporting detonation when really there isn't any.

[wobbly]

I use the Bosch sensor bolted directly to the head frame stay of a CR125 ( so its at right angles to the cylinder axis ) and it works perfectly.
On the TM KZ10 engines I have one longer head cover stud, with a small tophat spacer under the sensor, this also works perfectly.
The frequency/amplitude of a real deto event is very specific, and the little sensor light box I use I can wind up the sensitivity such that all the lower level led's flicker
when running the engine under normal load - and then only the big red warning light comes on when deto is present.
It also has a 0-5V output, showing the level of det on the data logger.

Re the R7376, apart from the Hp gain I found over all the other plugs I tested, the biggest issue it solved was two fold.
When a race engine started to detonate, the Iridium type plugs would crack the porcelain at the tip and fail quickly afterward by dropping pieces onto the piston.
The other plugs with big section earth electrodes have also killed several engines when this piece has dropped off.
The R7376 is expensive due to the tip porcelain construction, and the thin rare earth laser welded ground strap.
I have run hundreds of hours on these plugs and never had a failure ( inside the engine ).
Surely i would imagine a tuning issue that cracks the upper porcelain on a R7376 would do exactly the same to any plug ( or worse, inside a cylinder as I
discovered ).

[jfn2]

wobbly:
Thank you for the reply about the reeds and backups. What material are the backups made from and do you know what length they should be to the reed length? Are there different thicknesses for the backups? Also I see that the reed stops have a peculiar cut out to them. Or doesn't that matter? Thanks again.

[TZ350]

Enough motivation to stop procrastinating on the installation of a deto sensor. With a diameter of about 20mm at the mating side I am asking myself where to put it ideally (and where not to put it). As I run a paper gasket, I suppose somewhere on the water cooled cylinder would be nice, but there is not enough space available, except "on a stick" on one of the bolting areas for the head cover. Where du you guys put yours?


294192 294193


294223

http://www.ebay.com/itm/Knock-gauge-for-detonation-sensor-klopfsensor-NEW-/181309925670?pt=Race_Car_Parts&hash=item2a36e9e926&vxp=mtr




286854286853

Det Sensor

Follow the links back for more details.

[jfn2]

TZ350:
In attachment 294193 is the blue wired piece glued to the copper plate a temp sensor?

[husaberg]

"There’s very little all the factories agree on, but engine rotation is one of them After sunshine, rain and fresh air, my favourite natural phenomenon is gyroscopic effect. This is because we wouldn’t be able to ride motorcycles without it. If you don’t believe me, try this next time you’re out riding: when you stop at a traffic light, don’t put your feet down. (And don’t send me the bill.) A motorcycle’s spinning wheels create gyroscopic effect that keeps the machine going straight. The more speed, the more gyro and the more stability. This is all good, unless you are racing. Most racers don’t give a hoot about straight-line stability: they’re happy to hold on like gorillas on the straights, just so long as the bike will turn left or right in the blink of an eye. And this is why all premier-class Grand Prix manufacturers – possibly for the first time in history – now run their engines backwards. It may also explain why Marc Márquez’s COTA and Argentina victories were so huge – bigger than any dry-track wins from last year. When an engine runs forward (like most streetbikes) its crankshaft rotates the same way as the wheels, thus adding to the gyro effect, which makes it more difficult to turn into a corner or change direction. The obvious way to reduce gyro effect is to reverse the direction of engine rotation, so the reverse-rotating crank reduces the total gyro effect created by the fast-spinning wheels. The beneficial effects on the dynamics of a motorcycle are significant: 2the bike will turn quicker and change direction faster; a huge consideration in modern racing when most racetracks are very tight and twisty. A reverse-rotating engine also reduces wheelies, because the crank’s torque reaction pushes the front wheel down during acceleration, rather than lifting it (although this is less important than in the days of two-strokes, when crankshaft inertia was greater.) However, nothing is for free in racing. If you run the engine backwards the engine needs an extra jackshaft to keep the rear wheel turning the right way. That shaft absorbs a significant amount of horsepower, as well as increasing engine weight and dimensions. In theory, a reverse-rotating crank also increases understeer in corners, making the bike run wide on the exit, which can prevent the rider from getting on the throttle. But presumably all these costs are worthwhile because this year Honda reversed the engine rotation of their RC213V, the first time they’ve run an engine backwards since the days of the 500s. The last time Honda went backwards was in 1987. The first NSR500, born in 1984, was a real handful, partly because its V4 two-stroke engine ran forwards. The torque reaction from the forward-rotating crankshaft lifted the front during acceleration, causing plenty of problems for riders who spent too much time fighting wheelies instead of thinking about the next corner. The NSR ran backwards from 1987 and won eight of the last 13 500cc titles."

A bit off topic and random but...:bleh::cold:


All true but the 3 cylinder NS500 ran backwards as well.
I should note however, when the Screamer was reintroduced in the later 90's they kept the Balance shaft as Doohan said it steered better with it in place, that balance shaft of course ran forward.
Nearly All the other GP500's other thean the swiss auto had twin contra rotating cranks


The Velo Roarer had twin cotra rotating crankshafts mounted accross the frame with a direct shaft drive it is said to have steered beatifully.
326536326535326534
The MotoCzysz was a bike design that tried to minismise the gyro effect.
326537
http://motoczysz.com/motorcycles/c1_prototype
Regardsless of crank rotation the biggest conributer to the gyro effect on a bike is as far as i am aware the wheels.
All the honda CR125,250,500 shared very similar fame specs, the smaller cranked turn far better due to it small crankshaft the actually CR500 willfully resists any changes in direction.


The direction of crank spin has a huge influence on the bikes stability on corner entry and exit.
This is the precession effect,and we tried it experimentally when arguing about the crank spin of the BSL500 design.
Get a bicycle wheel and hold it in front of you by each end of the axle, spin it forwards or backwards then try to turn the axle to the left or right.
The precession force is huge considering the inertia of a tiny bicycle wheel/tyre, one direction of spin and the wheel "falls " into the turn direction
Spinning the opposite way its all but impossible to get the axle to rotate left or right by hand at all.
The amount of resisting force involved is simply staggering when you try this.

Cameron missed that the NS500 had a Jackshaft but the rest dovetails nicely.
https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=303366&d=1413015583https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=303360&d=1413015570
Enjoy, sorry about the words being cut of some of the scans, but i didn't do them. i only screendumped and tidied them up.
Note# The corporate pride mentioned, is not restrcted to the Japanese.
Ducati is a shining example. As is Porsche.

327070327071327072327073327074327075

[Pursang]

A key issue with the direction of engine rotation is piston thrust on the cylinder wall.

in a forward rotating engine the major thrust side is the back wall of the cylinder.
(In 2 Strokes, generally cooler and better lubricated due to intake flow)

Peak Force can be in the order of 8,000N

This can be 10 times the force on the minor thrust side.

If you want to reverse the rotation it might be wise to reverse the cylinder too.
And visa versa.

Cheers, Daryl.

[TZ350]

TZ350: 327076
Is the blue wired piece glued to the copper plate a temp sensor?

No. My knock sensor had two wires coming out of it. I used one for the signal and earthed the other one. The elastic glue is for vibration/strain relief so the wire does not break. I am not sure now if the earth was really necessary maybe both were individual knock sensor wires and the earth is the brass body of the knock sensor.

[husaberg]

A key issue with the direction of engine rotation is piston thrust on the cylinder wall.

in a forward rotating engine the major thrust side is the back wall of the cylinder.
(In 2 Strokes, generally cooler and better lubricated due to intake flow)

Peak Force can be in the order of 8,000N

This can be 10 times the force on the minor thrust side.

If you want to reverse the rotation it might be wise to reverse the cylinder too.
And visa versa.

Cheers, Daryl.

Which is why Yamaha did it first with the jackshaft on the TZ250H and then later with simplier Reverse Cylinder, It certainly wasn't for its pretty inlets.
The added bonus is less friction through loss of power sapping jackshaft and the potential for straighter exhausts.
Two strokes will run in either direction regarless of cylinder orientation, lightly tuned ones occasionally do it unintentionally.
A side not (i just thought of) a lot of shaft drive bikes run in reverse direction, Yet no one ever says they steer better than there chain drive sibblings?

[wobbly]

I tested the reverse cylinder friction theory when doing the BSL500.
Having the cylinder mounted " backwards " that is with the thrust face over the exhaust port made a repeatable 0.3Hp difference.
But the transfer duct entries were not matched, so that probably accounted for the power change more than any frictional gain/loss
The pipe was the same for the tests, but would have been dead straight or heavily curved in each case when bike mounted.

Yamaha didnt put the jackshaft into the 250 H model due to friction, it was to reverse the huge reliability issue they encountered with the piston port geometry prematurely
killing pistons in the G version.

Re the reed backups,the setups used at present are close to 50% length in the case of the TM and the CR I have been working on.
But both have much stiffer tip force on the bottom petals.
Both use carbon backups that are around 2/3 the thickness of the main petals, but cut away in the 1/2 moon shape, so contact is made
only on the outer sides.
The TM has stops around 1/3 length, the CR has full length stops.

[jfn2]

About the reed backups. How much is the backup curvature and what is the magmalyte material and are the backups made of the same material? If so, is this materials frequency the same as carbon fiber per same length and same thickness?

[husaberg]

I tested the reverse cylinder friction theory when doing the BSL500.
Having the cylinder mounted " backwards " that is with the thrust face over the exhaust port made a repeatable 0.3Hp difference.
But the transfer duct entries were not matched, so that probably accounted for the power change more than any frictional gain/loss
The pipe was the same for the tests, but would have been dead straight or heavily curved in each case when bike mounted.

Yamaha didnt put the jackshaft into the 250 H model due to friction, it was to reverse the huge reliability issue they encountered with the piston port geometry prematurely
killing pistons in the G version.

.

Wob i was meaning I believe they later just reversed the cylinders rather than use the earlier jackshaft as it had (from memory) cost them a couple of HP.
I was aware of the short piston life of the g model.:msn-wink:





The TZ twin for instance did the jackshaft to reverse the crank rotation only to increase piston life over a 100KM or so.
As i said in regards to the TZ750 to save cost. .





Husa was of course exaggerating about the piston mileage in the Yamaha TZ250G but apart from that I must agree with him on all accounts.
The TZ250G was remarkable. Power-wise its cylinder block was a big step forward, with better transfer ducts, smaller exhaust duct volumes and the huge inlet ports that were detrimental to piston life.
The following year Yahama reversed the direction of crankshaft rotation by means of the jackshaft, but we'd already found a much simpler solution: we reversed the cylinderblock on the 'G': piston problem solved.
In the Yamaha twins book there is quite a decent write up covering the TZs, that'swhere i got the 100 kms figure from
The H also from memory had beefier crankpins and a tighter press fit.

I am actually playing with a RD350 at the moment, i can't get over just how cramped the transfers are, Its amazing the TZs made any power at all in 350 form.

[Yow Ling]

Wob i was meaning I believe they later just reversed the cylinders rather than use the earlier jackshaft as it had (from memory) cost them a couple of HP.
I was aware of the short piston life of the g model.:msn-wink:







In the Yamaha twins book there is quite a decent write up covering the TZs, that'swhere i got the 100 kms figure from
The H also from memory had beefier crankpins and a tighter press fit.


H model had 2 seperate cranks with a coupling in the middle , on the outside of the coupling was the output gear that drove the jackshaft. So the crank was but a distant relative to the early TZs

[husaberg]

H model had 2 seperate cranks with a coupling in the middle , on the outside of the coupling was the output gear that drove the jackshaft. So the crank was but a distant relative to the early TZs
Different stroke as well.:laugh:
PS All the cranks were seperate as far as i am aware.
I will post what i have.

[husaberg]

The rest....

https://www.kiwibiker.co.nz/forums/album.php?albumid=4882

[adegnes]

Merry Christmas guys!


https://www.youtube.com/watch?v=8cFp6UgEMXY

[peewee]

any you guys tried these cages ? seems like they would need to be special ordered and maybe that adds a lot to the cost

http://www.skf.com/binary/tcm:12-32271/PEEK%20cages%20brochure%206372_EN_tcm_12-32271.pdf

[speedpro]

They look similar to what I've been calling phenolic resin cage bearings. I started using them when I had main bearing cages come apart in my Suzuki TS100 bucket. I've used them more recently in MB100 engines as main bearings. I've never had a problem with them. They weren't a whole lot more expensive if I recall.

[Frits Overmars]

any you guys tried these cages ? seems like they would need to be special ordered and maybe that adds a lot to the cost http://www.skf.com/binary/tcm:12-32271/PEEK%20cages%20brochure%206372_EN_tcm_12-32271.pdf
Aprilia RSA crankshaft bearings. Look familiar?
327149 327150

[peewee]

ive seen them frits but wasnt sure of the material. pa66 is common so i assumed thats what it might of been

[husaberg]

http://www.superkart.it/engine-spare-parts/bearings/bearings/crankshaft/crankshaft-roller-bearing-skf-6205-bc1-1442-b-tm-03029?cPath=92_281&
http://www.superkart.it/images/ricambi_motori/SK1232.jpg

[adegnes]

http://www.superkart.it/engine-spare-parts/bearings/bearings/crankshaft/crankshaft-roller-bearing-skf-6205-bc1-1442-b-tm-03029?cPath=92_281&
http://www.superkart.it/images/ricambi_motori/SK1232.jpg
Made in 6203/04 also you think? Having trouble finding them in the SKF bearing finder.


From the same site
http://www.superkart.it/engine-spare-parts/special-parts/special-piston-pin-for-125cc-kz-flat-model
http://www.superkart.it/images/ricambi_motori/SK1333.jpg

Not exactly cheap...

[Yow Ling]

H model had 2 seperate cranks with a coupling in the middle , on the outside of the coupling was the output gear that drove the jackshaft. So the crank was but a distant relative to the early TZs

Hey Husa , found a good picture describing the above

327154

[husaberg]

Hey Husa , found a good picture describing the above

327154

It is a very nice picture, i think i will harvest it.;)
https://www.kiwibiker.co.nz/forums/album.php?albumid=4882


Made in 6203/04 also you think? Having trouble finding them in the SKF bearing finder.


From the same site
http://www.superkart.it/engine-spare-parts/special-parts/special-piston-pin-for-125cc-kz-flat-model
http://www.superkart.it/images/ricambi_motori/SK1333.jpg

Not exactly cheap...

Euros aye eeeek.....
Try KTM85 they have a plastic cadged roller bearing not sure re the size though
But its in the Pro X cattledog though (which i can't find at the moment either lol)

NJ206 ECP
Inside Diameter: 30mm
Outside Diameter: 62mm
Width: 16mm

[jamathi]

Aprilia RSA crankshaft bearings. Look familiar?
327149 327150

Those bearings were especially made for Aprilia.
We had lots of problems because the 'shoulder' used to break off.
So they removed it, and instead supplied a loose ring.
They were used on all Aprilia engines, not just the RSA

[Yow Ling]

Those bearings were especially made for Aprilia.
We had lots of problems because the 'shoulder' used to break off.
So they removed it, and instead supplied a loose ring.
They were used on all Aprilia engines, not just the RSA

Hello Jan, Have a happy Christmas, best wishes to you and your family, keep looking after the animals

[koenich]

Made in 6203/04 also you think? Having trouble finding them in the SKF bearing finder.

I use SKF NJ 204 ECP C3 or FAG NJ 204 E TVP2 C3 (equivalent to the 6204 bearings) in my 50cc Derbi engine. 0,2...0,3 axial play and I never had a failure with up to 50h runtime, thats about the time the better crankshafts last :facepalm:

[adegnes]

I use SKF NJ 204 ECP C3 or FAG NJ 204 E TVP2 C3 (equivalent to the 6204 bearings) in my 50cc Derbi engine. 0,2...0,3 axial play and I never had a failure with up to 50h runtime, thats about the time the better crankshafts last :facepalm:

Thanks!
..............

[breezy]

https://www.acu.org.uk/news/track-racing/.... :facepalm: british motorsport could end.....

[lodgernz]

https://www.acu.org.uk/news/track-racing/.... :facepalm: british motorsport could end.....

Not just British motorsport: ALL European motorsport could end. Funniest and scariest is that this would also apply to lawnmowers and mobility scooters.

[husaberg]

https://www.acu.org.uk/news/track-racing/.... :facepalm: british motorsport could end.....

Jus as well the IOM is not part of Britain, neither is Ireland.:msn-wink:

[WilDun]

Jus as well the IOM is not part of Britain, neither is Ireland.:msn-wink:

The IOM and Northern Ireland are British. - Southern Ireland is a republic, they officially separated from Britain in 1949 (I think).
It's funny that when Eugene Laverty wins he prefers to have the Irish national anthem played and under the Irish Tri colour flag, whereas his brother Michael uses the Union Jack and has the British national anthem playing,
They come from Northern Ireland but at least now they can voice their preferences without controversy. (progress I guess!).

Both motorcycle racing and Rugby don't seem to recognize borders in Ireland and that's good!

[husaberg]

The IOM and Northern Ireland are British.
You are right they are british but they are still not part of the UK, They have their own laws including speed and tax.
Kind of like the cook islands are to us.

[WilDun]

Not just British motorsport: ALL European motorsport could end. Funniest and scariest is that this would also apply to lawnmowers and mobility scooters.

We could help out by bringing the TT over here, plenty of scope for that in NZ! :yes:

[WilDun]

You are right they are british but they are still not part of the UK, They have their own laws including speed and tax.
Kind of like the cook islands are to us.

No Husa that's not really the case at all, England, Scotland, Wales, IOM, and N Ireland are all recognized as being (slightly) different people and are given some autonomy, but are all governed by British constitution and are considered to be part of the UK. (nobody worries anymore anyway), but ...... let's hope that there will be a solution which suits all of Europe (they will find one) If they could sort Hitler out, then this will be a dawdle!

[husaberg]

No Husa that's not really the case at all, but let's hope that they find a solution which suits all of Europe (and they will) If they could sort Hitler out then this will be a dawdle!


The UK consists of four countries—England, Scotland, Wales and Northern Ireland.[16] The last three have devolved administrations,each with varying powers, based in their capitals, Edinburgh, Cardiff and Belfast, respectively. The nearby Isle of Man, Bailiwick of Guernsey and Bailiwick of Jersey are not part of the United Kingdom, being Crown dependencies with the British Government responsible for defence and international representation.https://en.wikipedia.org/wiki/United_Kingdom
It will blow over much like than silly quasi ban on childrens motorbikes in the USA a few years ago.
The yanks did some legislation to ban toys with a certain lead content (due to lead painted chinese toys) the Japanese would not import motorbikes for kids like the CRF50 as the lead content in the spokes and solder for wiring exceded it.

[JanBros]

David Emmet wrote a nice piece on the subject : https://motomatters.com/analysis/2016/12/23/no_the_end_is_not_nigh_for_motorsport_in.html

[WilDun]

It will blow over much like than silly quasi ban on childrens motorbikes in the USA a few years ago.

Ok, well thank God for Google ...Eh! - the reality for most people there is not quite that clear cut, but who cares! - I've also been told that it's not all that long ago since the Isle of Man was actually ruled by Denmark!

And yes it is just another case of "the sky is falling" - I think that we can overcome anything if we try hard (and feed in plenty of cash).

[lodgernz]

Jus as well the IOM is not part of Britain, neither is Ireland.:msn-wink:

True, but Ireland (Eire) IS part of the EU, so is at the same risk as the rest of Europe and the UK.
However, if Emmett is correct, it's probably not going to happen anyway.
But then again, it is the EU, where massive stupidity has plenty of precedent.

[husaberg]

True, but Ireland (Eire) IS part of the EU, so is at the same risk as the rest of Europe and the UK.
However, if Emmett is correct, it's probably not going to happen anyway.
But then again, it is the EU, where massive stupidity has plenty of precedent.

Then again it won't affect us (well it shouldn't) it might even lead to more of a off season influx, like the good old days.
Pretty sure road racing has been banned in Switzerland since at least the 40's thats why they used to go nuts for hill climbing.
Also Pretty sure they never let women vote until the late 60's either.:innocent:
plus they have laws on running washing machines after 9pm and such like. ( i am not kidding)
So who knows, cotton wool and bubblewrap sales might just go through the roof

[breezy]

http://www.gpracing.hu/index.php?view=detail&id=1072&option=com_joomgallery&Itemid=58

[husaberg]

http://www.gpracing.hu/index.php?view=detail&id=1072&option=com_joomgallery&Itemid=58

Cheers, some intersting pics their.

[breezy]

Injecting fuel/ air back into the cylinder via the exhaust port at the appropriate time? or pressure relief from some where? or are those pictures from something else?

[husaberg]

Injecting fuel/ air back into the cylinder via the exhaust port at the appropriate time? or pressure relief from some where? or are those pictures from something else?

The other pics with the sensor in the ex manifold are not named as being RYGER?
All these ones are though.
https://www.kiwibiker.co.nz/forums/album.php?albumid=5071
327396327397327398327399327400327401

[peewee]

Here is the TM parts page.
There is a newer reed petal set, that makes better power with both bottom backups pointing inward
and the single top one pointing away from the petal.

hey mate I picked up a couple sets of 2petal thin carbon fibres. one set for the mains and one for some stiffeners. tested a small diamond bit on a old carbon petal and it cut them just dandy so I can make stiffeners as desired. is that half moon the go ? im guessing it adds some extra tension without putting a fulcrum point laterly across the face of the main petal ? oh ya hows the head going ? :drinknsin

[adegnes]

Eu is going for the Norweigan model... We were trying to get permission for a small outdoor kart track to be built where I live. Declined, to few ambulances in town for it to be safe they said. Amateur racing like your bucket thing is strictly prohibited over here of course.

The PowerSpark ignition unit I'm running on my Peugeot Spx.

https://www.youtube.com/watch?v=gQV_OyDi_4M

[husaberg]

Eu is going for the Norweigan model... We were trying to get permission for a small outdoor kart track to be built where I live. Declined, to few ambulances in town for it to be safe they said. Amateur racing like your bucket thing is strictly prohibited over here of course.

The PowerSpark ignition unit I'm running on my Peugeot Spx.

https://www.youtube.com/watch?v=gQV_OyDi_4M

when you said Norweigian models:innocent:
Power Spark is two words for those that wish to google it
http://www.power-spark.de/index_en.html

[Muciek]

And the story continues... It looks like curve of the normal 2t there is still a "hole" before the powerband.

https://www.facebook.com/photo.php?fbid=10206184705895689&set=a.10206184705695684.1073741874.1805454134&type=1&theater

[koenich]

thats a BMEP of >19 bar...uhm yeah

[adegnes]

I'm dynoing the Spx again tomorrow, but can give you a sneak peak at the numbers already.

327417

The secret is no fuel in the premix.

[F5 Dave]

Wicked. Next an amsoil zealot will be along to tell you'd break a hundy.

[Flettner]

And the story continues... It looks like curve of the normal 2t there is still a "hole" before the powerband.

https://www.facebook.com/photo.php?fbid=10206184705895689&set=a.10206184705695684.1073741874.1805454134&type=1&theater
So what are we looking at? First engine didn't do 70 hp and the production engine is only 40 hp? Are these predicted figures or real? Or is the lower curve some sort of torque curve? Here we bloody go again!

[husaberg]

So what are we looking at? First engine didn't do 70 hp and the production engine is only 40 hp? Are these predicted figures or real? Or is the lower curve some sort of torque curve? Here we bloody go again!

Wob asked this question.
What has happened to the 50 previous " production " engines for homologation that made 70 Hp and reved to 30,000.
Luc answered this to a a question about the graph
The red is the special Ryger, the yellow the standard version. The lower 2 are torquelines.

[Flettner]

So that's a BMEP of 270.4 we are comfortable with that? And where is this 30,000 rpm bullshit? This almost seems possible now with some mechanical reality admitted.
Original claim BMEP was 200 ish at 17500 / 18000 I believe, clearly the revs have had to be dropped to make it reliable but I would have thought the BMEP would have dropped as well? Lucky we don't know what we are talking about or this new Ryger power curve would not be possible. Luc says they have dropped the rev's to make the engine more usable, I guess that means so you can get more than one lap out of it:Oops:
Case of another bit of fake facebook news I think, left had column divide by two perhaps.

[JanBros]

I'm dynoing the Spx again tomorrow, but can give you a sneak peak at the numbers already.

327417



I think you have one zero too much. surely you do not want us to believe your spx runs up to a wooping 5.000 rmp :bs:

[adegnes]

I think you have one zero too much. surely you do not want us to believe your spx runs up to a wooping 5.000 rmp :bs:

Oops, missed that one.
The correct numbers are of course 900hp @ 500rpm
Still not bad for 50cc.

[wobbly]

So now we have a completely new engine tune, and a dyno graph.
Problem is the "dyno " software is one I have never seen before,so one tends to start thinking this is just another scam,just like all
the other groundbreaking announcements that have proven to be utter bullshit.
But the restricted upper rev range is what I would expect from a 90mm rod on a 54.5mm stroke - the angular load on the vertical bearing must be really bad.

Yes I asked the question about the original 50 engines , as we were told we couldnt have one as they were all sold.
Now they have disappeared, and another " better " one has suddenly appeared.

The ONLY positive I have taken so far from any of this is that Frits seems to be truly convinced that what he drove all that time ago,
was pretty amazing.

Wish it were, I really do.

[TZ350]

Page 1630....

Some links to YouTube clips of a couple of two stroke bikes modified for EFI.

Yamaha YZ250.

https://youtu.be/hOGZ5llowoU

https://youtu.be/UEQli7nuak4

https://youtu.be/1YG9ko8-Nwk

Kawasaki BigHorn.

https://youtu.be/eleqBGvOM4M

https://youtu.be/ifSEql1X4R0

https://youtu.be/CnIemdISKrM

Yamaha R5

https://youtu.be/qzVHgHJ9PWI


race 1 from weekend
https://youtu.be/VjCtIDTSKRY

[sb07]

The ONLY positive I have taken so far from any of this is that Frits seems to be truly convinced that what he drove all that time ago,
was pretty amazing.

Wish it were, I really do.

Santa Claus does not exist :shifty:

[breezy]

[QUOTE=wobbly;
"But the restricted upper rev range is what I would expect from a 90mm rod on a 54.5mm stroke - the angular load on the vertical bearing must be really bad."



Wobbly could this be reduced by offsetting the big end or small end of the conrod/lower piston connection?:sherlock:

[FastFred]

.

https://www.facebook.com/photo.php?fbid=10206184705895689&set=a.10206184705695684.1073741874.1805454134&type=1&theater

327423

Fairly narrow power spread, 3.000 rpm, TeeZee managed over 4.

[jonny quest]

.

https://www.facebook.com/photo.php?fbid=10206184705895689&set=a.10206184705695684.1073741874.1805454134&type=1&theater

327423

Fairly narrow power spread, 3.000 rpm, TeeZee managed over 4.

I see just the opposite

[F5 Dave]

I wish people would use dyno curves all showing where zero revs is. Gives perspective where if you start a curve at 8000 odd it can make my 50 look respectable.

[FastFred]

... the restricted upper rev range is what I would expect from a 90mm rod on a 54.5mm stroke - the angular load on the vertical bearing must be really bad.

327425

The angular load may be bad but the friction does not need to be if a rolling element can be used on both thrust faces. If there was some minimal clearance between the cross head and rolling element then the outer race of the rolling elements would not have to reverse direction when the stroke reverses.

The inertia of the rolling element would keep it spinning in the original direction as the load swapped from side to side. The outer race would spin up in much the same way as when you hold the inner of a bearing and spin the outer up by hand.

[Flettner]

327425

The angular load may be bad but the friction does not need to be if a rolling element can be used on both thrust faces. If there was some minimal clearance between the cross head and rolling element then the outer race of the rolling elements would not have to reverse direction when the stroke reverses.

The inertia of the rolling element would keep it spinning in the original direction as the load swapped from side to side. The outer race would spin up in much the same way as when you hold the inner of a bearing and spin the outer up by hand.

I'm not sure the side load would be so bad in the Ryger system. If the sliding surfaces are, say, hard chrome (plated) on aluminium bronze with oil, that would be a whole lot better than an aluminium piston against a bore with minimal lubrication and lots of holes in it (ports). I imagine the short rod is two fold, try and keep the engine short (although why bother as it's already a tall engine anyway and 5mm isn't going to make bugger all difference) and perhaps whats required in regards to the combustion burn. The shorter rod will have the piston a little more time up top where the 'magic' apparently takes place. No, I think the real problem is the mass of the piston pulling the whole system apart at elevated rpm's, there is no way out, it's a large oscillating component.

[Frits Overmars]

The angular load may be bad but the friction does not need to be if a rolling element can be used on both thrust faces. If there was some minimal clearance between the cross head and rolling element then the outer race of the rolling elements would not have to reverse direction when the stroke reverses. The inertia of the rolling element would keep it spinning in the original direction as the load swapped from side to side.That inertia would try to keep the outer race spinning at some constant speed.
But the speed of the crosshead is anything but constant, so there would still be a lot of slip between the two.
What's worse: the bearing cages with their contents would be subject to continuous acceleration and deceleration, causing friction and heat in the bearings.
This is already a burden in big end bearings, where the rate of rotation fluctuates only mildly, compared to what you are proposing.


The shorter rod will have the piston a little more time up top.After the holidays, when eventual ethanol-effects have worn off, you might want to give this some more thought Neil :msn-wink:.

[TZ350]

I wish people would use dyno curves all showing where zero revs is. Gives perspective where if you start a curve at 8000 odd it can make my 50 look respectable.

327432

I can see what you mean.

Green 50% throttle and recording started at 4,000rpm. Red 100% throttle and recording the run started at 8,500 rpm.

Interesting that 50% throttle gives greater than 80% of the power and its diminishing returns after that with 80% throttle pretty much the same as 100% or WOT.

The Team ESE Dynojet chooses its own graph axis according to what was recorded. To display from zero rpm would require starting at zero rpm. As the Beast idles at about 3.500 rpm I have to start a dyno pull at 4,000 or so. And for practical purposes I am not always interested in anything less than the power curve itself.

But I agree, a graph starting at zero does give a better perspective of the real shape of the power curve and should be mandatory reporting so one can truly compere apples with apples.

[jasonu]

I wish people would use dyno curves all showing where zero revs is. Gives perspective where if you start a curve at 8000 odd it can make my 50 look respectable.

Dave mate it would take more than that to make your 50 curve look decent.
Happy new year to you and your tribe!!!!!

[mr bucketracer]

I wish people would use dyno curves all showing where zero revs is. Gives perspective where if you start a curve at 8000 odd it can make my 50 look respectable.thats the trouble with 2 strokes , only four strokes can do that (-;:innocent:

[TZ350]

After a bit of a break I have come back to the EFI project. Flettner and Speedpro had both suggested to me that my previous problems may not be the map itself but could easily be due to a simple option box in the software somewhere that needs to be un-ticked.

After carefully looking through the 100 odd fine tuning option box's I found a likely suspect. Its function seemed to be to completely shut the fuel off during periods of over run. This is to stop bore wash from excess raw fuel during long down hill runs. Great idea if you are riding a 4T scooter in the mountains.

The option box field is for entering the fuel resuming engine speed after the fuel was shut off in over run. The default was 3,800 rpm, ok for a 4T scooter but kind of low for a 13,000 rpm 2T but explains why the bike would shut down and not come on the throttle again after apexing a corner, the dam thing would not fire up again until it had nearly come to a stop.

I re set the fuel resuming option box to 12,000 rpm and a quick test up the drive showed a lot of promise with no hesitation when coming back on the throttle.

327442

Bike setup with a laptop for auto tuning the EFI map under real riding conditions.

This weekend with Speedpro's help I am hoping to get the bike on a dyno that has a load break so the engine can be held under a steady load. The Ecotrons EFI software has a auto tune function and if the load rpm and TPS can be held steady for a short period the software will auto adjust the corresponding map cells. The whole map can be auto tuned in steps this way.

327441

Wide band O2 sensor for auto tuning. Initially I had it in the header like 4T's do. but Wobbly suggested this is a better place on a 2T to get a reliable reading. Sure seemed to work ok and responded to air fuel ratio changes during a quick ride around the car park.

327440

All packed and ready for plan A, a trip to the dyno, plan B is to find a quiet back road to putter up and down while the laptop does its auto tuning trick.

[adegnes]

After a bit of a break I have come back to the EFI project. Flettner and Speedpro had both suggested to me that my previous problems may not be the map itself but could easily be due to a simple option box in the software somewhere that needs to be un-ticked.

After carefully looking through the 100 odd fine tuning option box's I found a likely suspect. Its function seemed to be to completely shut the fuel off during periods of over run. This is to stop bore wash from excess raw fuel during long down hill runs. Great idea if you are riding a 4T scooter in the mountains.

The option box field is for entering the fuel resuming engine speed after the fuel was shut off in over run. The default was 3,800 rpm, ok for a 4T scooter but kind of low for a 13,000 rpm 2T but explains why the bike would shut down and not come on the throttle again after apexing a corner, the dam thing would not fire up again until it had nearly come to a stop.

I re set the fuel resuming option box to 12,000 rpm and a quick test up the drive showed a lot of promise with no hesitation when coming back on the throttle.

327442

Bike setup with a laptop for auto tuning the EFI map under real riding conditions.

This weekend with Speedpro's help I am hoping to get the bike on a dyno that has a load break so the engine can be held under a steady load. The Ecotrons EFI software has a auto tune function and if the load rpm and TPS can be held steady for a short period the software will auto adjust the corresponding map cells. The whole map can be auto tuned in steps this way.

327441

Wide band O2 sensor for auto tuning. Initially I had it in the header like 4T's do. but Wobbly suggested this is a better place on a 2T to get a reliable reading. Sure seemed to work ok and responded to air fuel ratio changes during a quick ride around the car park.

327440

All packed and ready for plan A, a trip to the dyno, plan B is to find a quiet back road to putter up and down while the laptop does its auto tuning trick.

:2thumbsup:2thumbsup

[adegnes]

Duplicate post...

[adegnes]

I've had the Spx on the dyno again, now with some serious weight added to the carb.

327454

Actually seemed to help, although it was "foaming", about half of the fuel in the bowl remained a liquid.

Peak power is still low, 13.5ish rwhp at 13-13.5k rpm, not 18ish at 15.5k like engmod is predicting.
1100f peak EGT

I'll have to find time for a long session with jetting and ignition timing and quit mocking about. If that doesn't do anything I too am starting to think engmod needs different temp or comb data for low displacement engines.

[JanBros]

So now we have a completely new engine tune, and a dyno graph.
Problem is the "dyno " software is one I have never seen before,so one tends to start thinking this is just another scam,just like all
the other groundbreaking announcements that have proven to be utter bullshit.
But the restricted upper rev range is what I would expect from a 90mm rod on a 54.5mm stroke - the angular load on the vertical bearing must be really bad.

Yes I asked the question about the original 50 engines , as we were told we couldnt have one as they were all sold.
Now they have disappeared, and another " better " one has suddenly appeared.

The ONLY positive I have taken so far from any of this is that Frits seems to be truly convinced that what he drove all that time ago,
was pretty amazing.

Wish it were, I really do.

Bob Van der Zijden's last opinion on the Ryger :


RYGER is MOST probably a real cheat! And our beloved dreamers Frits Overmars and especially wanker LUC FOEKEMA were used by RYGER. Nephew FOEKEMA is still dreaming, Frits got awake in time and LUC is still living on f...ing cloud # 9. A major business player in the Karting world in Holland was cheated by RYGER for over 7000 euros some years ago.

http://www.pit-lane.biz/t6315p375-2stroke-ryger-engine#327801

[_____]

[...]
Peak power is still low, 13.5ish rwhp at 13-13.5k rpm, not 18ish at 15.5k like engmod is predicting.
1100f peak EGT

I'll have to find time for a long session with jetting and ignition timing and quit mocking about. If that doesn't do anything I too am starting to think engmod needs different temp or comb data for low displacement engines.

I came to the same conclusion:


Hi wob and everyone!
I have a general question on the exhaust temperatures. Are they a depending on the cc of the engine?
I worked on a 50cc engine with engmod and the estimated peak of the simulation was at least 2000 RPM higher than in real life. In fact, i needed to make the temperature on the exhaust unphysically low (150°C) to get the rpm range to suit the reality.
I would suggest the temperature to be a formula of the cubic capacity, bmep and blowdown (more blowdown meaning less backflow to the transfers, thus the first gas scavenged and lost through the exhaust will be way cooler than with less blowdown)



I am currently working on a foul-stroke and am reading the 4T Blair for that purpose. On that book he describes the same issue about unphysically low exhaust gas temperatures "in reality"

[oldjohnno]

I've had the Spx on the dyno again, now with some serious weight added to the carb.


Actually seemed to help, although it was "foaming", about half of the fuel in the bowl remained a liquid.



Don't underestimate the effects of foamed fuel. I had problems with vibration related fuel foaming in a Mikuni TMX; the engine would accelerate nicely on the dyno until the rpms reached a point where the shakes became too much, whereupon the engine would simply stop firing altogether. The rpms would then drop a few hundred, the engine would fire again and the cycle would repeat over and over, sounding like it was bouncing off a rev limiter. A change to the crank BF eliminated the issue entirely, though it was never a problem with the VM carb.

[adegnes]

Don't underestimate the effects of foamed fuel. I had problems with vibration related fuel foaming in a Mikuni TMX; the engine would accelerate nicely on the dyno until the rpms reached a point where the shakes became too much, whereupon the engine would simply stop firing altogether. The rpms would then drop a few hundred, the engine would fire again and the cycle would repeat over and over, sounding like it was bouncing off a rev limiter. A change to the crank BF eliminated the issue entirely, though it was never a problem with the VM carb.

Sounds familiar.
I'm uploading the dyno video as we speak, you can see/hear the rev limit effect a couple of times.
There's no felt vibration in the handlebars/seat to speak of anymore after rebalancing to 58% bf. With the spring loaded swinging mounts, could my engine be too well isolated from the frame, not allowing it to soak up the vibration?
Have to get my hands on a few different carbs and try.

[adegnes]

The dyno video.


https://www.youtube.com/watch?v=fZ9sK9Ws0L8

[Michael Moore]

Don't underestimate the effects of foamed fuel.

Gordon Jennings mentioned solving problems at Daytona on several bikes by wrapping lead wire around the carb(s) to change their resonant frequency.

[adegnes]

Gordon Jennings mentioned solving problems at Daytona on several bikes by wrapping lead wire around the carb(s) to change their resonant frequency.

The added weight did seem to help. I'll see if I can find some lead to add even more without the bulk. A brace to the frame could probably solve this, complicated with the moving engine.

[oldjohnno]

The added weight did seem to help. I'll see if I can find some lead to add even more without the bulk. A brace to the frame could probably solve this, complicated with the moving engine.

When I had fuel frothing problems the engine would cut right out at the critical rpms but unlike your bike the fuel bowl never overflowed a drop - there didn't appear to be any problem with maintaining the fuel level in the bowl and this makes me think that we are looking at two different conditions. I assume you use a spring-loaded rubber or viton tipped float needle? I really enjoy your videos BTW, very well done.

[adegnes]

When I had fuel frothing problems the engine would cut right out at the critical rpms but unlike your bike the fuel bowl never overflowed a drop - there didn't appear to be any problem with maintaining the fuel level in the bowl and this makes me think that we are looking at two different conditions. I assume you use a spring-loaded rubber or viton tipped float needle? I really enjoy your videos BTW, very well done.

Thanks!
Yep, spring loaded rubber tip. I think it's time to try a different carb. Maybe my Oko is particularly sensitive to vibration...

[TZ350]

As a matter of interest. I once worked with a TQ midget race car. We found you had to remove the float needle from the carburettor when the midget was being trailered to a race meeting. Leave the float needle in and it would vibrate around and wear out the needle and seat in very quick time.

[adegnes]

As a matter of interest. I once worked with a TQ midget race car. We found you had to remove the float needle from the carburettor when the midget was being trailered to a race meeting. Leave the float needle in and it would vibrate around and wear out the needle and seat in very quick time.

Hmm. Maybe my needle/seat is trash. I can't see anything wrong with it, but then again I need glasses and don't own any.

[husaberg]

Gordon Jennings mentioned solving problems at Daytona on several bikes by wrapping lead wire around the carb(s) to change their resonant frequency.


Kevin Cameron discussed (An itailian ducati tuner I can't think of his name edit later it was Actually Gordon Jennings own Aermacchi 250 :laugh:) in TDC 1. He was using lead weights on remote float bowls on Ducatis etc. The fuel was vibrated away and formed foam with air at certain frequencies. The theory was to tune to a complimentary frequency or harmony by trail and error much it like a guitar or piano.
I have seen it done with British bikes with TT and GP carbs as well. These generally have a separate mount to isolate them further. from memory the square matchblock float chambers are worse but they may have a pivoting float rather than a pole slider float valve.
(Note the pommy bikes had solid mounted carbs as did the Jenning Macchi.)
Maybe you inlet rubber is just too hard.

Cameron also mentioned that the first KR3 was near impossible to carburate on account of it severe vibration.

The fuel frothing (i think) does two things first it gives an inconsistant mixture that can be actually be alternating between rich and lean depending on the RPM.
It can also i believe shuts off the fuel supply, as the frothy mixture raises the float level.
The liquid fuel can also be diverted directed away from the mainjet. being replaced by a bubbly air/fuel mix
Some mikunis and Keihins have jet sheilds that might help. Aftermarket FCR bowls have deeper wells and different designs to overcome frothing on whoops and similar conditions.
These below are stock CRF230.
327510327511327513

This is the mikuni part
327514327515327516

[TZ350]

As a matter of interest. I once worked with a TQ midget race car. We found you had to remove the float needle from the carburettor when the midget was being trailered to a race meeting. Leave the float needle in and it would vibrate around and wear out the needle and seat in very quick time.
Hmm. Maybe my needle/seat is trash. I can't see anything wrong with it, but then again I need glasses and don't own any.

No, probably not. I just posted that as an example of the weird shit that happens and can take a while to figure out.

[Grumph]

As a matter of interest. I once worked with a TQ midget race car. We found you had to remove the float needle from the carburettor when the midget was being trailered to a race meeting. Leave the float needle in and it would vibrate around and wear out the needle and seat in very quick time.

Pretty sure i know which carbs they were, LOL. Never had a problem with the cars I looked after, but back when single cam Hondas were common one guy I knew reckoned the best spot for the carbs when towing was on the rear parcel shelf of the tow car. The brass floats would bend and stuff up the fuel levels if left on the race car. But the carbs were the least of his problems...

[oldjohnno]

The old Amal concentrics had a fine gauze sock over the main jet. At first I thought it was just some sort of strainer but apparently it's to help with frothing. I wonder if some of this stuff would help?

https://www.youtube.com/watch?v=yfE1v65fNZI

[adegnes]

The old Amal concentrics had a fine gauze sock over the main jet. At first I thought it was just some sort of strainer but apparently it's to help with frothing. I wonder if some of this stuff would help?

https://www.youtube.com/watch?v=yfE1v65fNZI
Isn't this just how those "stones" on the intake line in chainsaw fuel tanks work?
That fine gauze sock is interesting and worth a try, I'll see if I can find something suitable.

[Flettner]

Sooo, spark plugs, I'm sure it's all been said (I didn't listen) but if in a twostroke detonation is a limit to ultimate power and it seems careful attention to the spark plug surroundings (cooling water) helps, would a smaller spark plug offer less 'hot area' to light up detonation? I have 8mm plugs in 9 heat range, a lot less metal and spark plug. A lot more water cavity. ???

[Michael Moore]

We found you had to remove the float needle from the carburettor when the midget was being trailered to a race meeting. Leave the float needle in and it would vibrate around and wear out the needle and seat in very quick time.

This was found to be a problem in the USA with new automobiles transported by rail from the factory. They were getting "false Brinelling" on the wheel bearings from the vibration with the otherwise stationary bearings. The bearings would fail soon after leaving the dealer's lot.

https://en.wikipedia.org/wiki/False_brinelling

[adegnes]

Was granted some dyno time later today by girlfriend.
Gameplan:

1. Go over and tighten mounts as much as possible without restricting movement, shim out where/if necessary.

2. Rubber hose extension on intake to make it softer, will be hopelessly long but for testing purposes it'll be fine.

3. "sock" over jet block, material from fuel filter or something.

4. Better jet "shield".

4. Different carb, my neighbor maybe had one lying around.

[adegnes]

I'll try to make something similar to this

http://www.jokermachine.com/media/catalog/product/cache/1/thumbnail/448x/9df78eab33525d08d6e5fb8d27136e95/c/a/carbslosh3_1_4.jpg

[husaberg]

Was granted some dyno time later today by girlfriend.
Gameplan:

1. Go over and tighten mounts as much as possible without restricting movement, shim out where/if necessary.

2. Rubber hose extension on intake to make it softer, will be hopelessly long but for testing purposes it'll be fine.

3. "sock" over jet block, material from fuel filter or something.

4. Better jet "shield".

4. Different carb, my neighbor maybe had one lying around.
Methodical one thing at a time?
327543
or everything at once?
327542

[adegnes]

For once I think I'll go with the pointy ear approach.

[adegnes]

Snuck out and had a quick look at the pwk bowl and jet block.
The main jet is "shielded" well from factory. Without making a well and extending the jet, a small piece of foam is all that will fit.
Enough to help you think? Guess there's only one way to find out.

327544

I could make a well and maybe extended the main jet with a short piece of tubing.

[husaberg]

These are available for mikunis
327548327549327550
There is also larger float bowls available for larger Keihins but they are very spendy.

All these though are more bandaid fixes for what is likely a BF issue. :)

[adegnes]

These are available for mikunis
327548327549327550
There is also larger float bowls available for larger Keihins but they are very spendy.

All these though are more bandaid fixes for what is likely a BF issue. :)

Shh..

Where do you draw the line between a plenum and the intake sizevise? Maybe I could resurrect TZ's plenum idea, mount the carb to the frame and use a flexible hose between it and the plenum.

[philou]

Boyesen sells bowl that would reduce the emulsion. I do not know if it really works

http://www.solex-competition.net/virtual_repair_center/images/uploads/riritrep/Cuve%20BOYESEN%20anti-emulsion.jpg

http://www.solex-competition.net/virtual_repair_center/images/uploads/riritrep/Cuve%20BOYESEN%20anti-emulsion%201.jpg

Look fuel inside the bowl Lectron carb at 1'37 m :blink:

http://m.youtube.com/watch?v=ZgbXSJ-aoQY

[Frits Overmars]

Rubber hose extension on intake to make it softer, will be hopelessly long but for testing purposes it'll be fine.Yeah, right. It may solve your vibration problems but it will hopelessly upset inlet resonance, unless you compensate with a later-closing disk or/and a larger crankcase volume, in which case you alter more than one crucial thing and you won't know what did what.


I'll try to make something similar to this
http://www.jokermachine.com/media/catalog/product/cache/1/thumbnail/448x/9df78eab33525d08d6e5fb8d27136e95/c/a/carbslosh3_1_4.jpgThat's an idea I like very much. I've seen deepened float bowls before but always in combination with the main jet at its original height.
Lowering the main jet as well may make all the difference, possibly even without the red foam. But as Husaberg says, the real goal should be to eliminate the vibration.

Foaming fuel in the float bowl makes the fuel less dense, so the various fuel jets that are really volume-flow controlling devices, may pass less fuel mass.
The diminished fuel density will also offer less buoyancy to the float, so the fuel level will become higher, partly compensating, completely compensating or overcompensating for the diminished mass flow through the jets. In short: carb vibration may enrich the mixture, or make it leaner, or both, at various revs.
How about a nice simple injection system?

[adegnes]

Yeah, right. It may solve your vibration problems but it will hopelessly upset inlet resonance, unless you compensate with a later-closing disk or/and a larger crankcase volume, in which case you alter more than one crucial thing and you won't know what did what.

That's an idea I like very much. I've seen deepened float bowls before but always in combination with the main jet at its original height.
Lowering the main jet as well may make all the difference, possibly even without the red foam. But as Husaberg says, the real goal should be to eliminate the vibration.

Foaming fuel in the float bowl makes the fuel less dense, so the various fuel jets that are really volume-flow controlling devices, may pass less fuel mass.
The diminished fuel density will also offer less buoyancy to the float, so the fuel level will become higher, partly compensating, completely compensating or overcompensating for the diminished mass flow through the jets. In short: carb vibration may enrich the mixture, or make it leaner, or both, at various revs.
How about a nice simple injection system?

Played around with jet sizes and foam around the jet on the roller today, not much luck.
I'll solder up an extended emulsion tube and make a well in my float bowl.

Injection is starting to sound tempting!

[Frits Overmars]

I'll try to make something similar to this
http://www.jokermachine.com/media/catalog/product/cache/1/thumbnail/448x/9df78eab33525d08d6e5fb8d27136e95/c/a/carbslosh3_1_4.jpgWhat are you going to call your next video? Deep Float ?:msn-wink:

[adegnes]

What are you going to call your next video? Deep Float ?:msn-wink:

:laugh::laugh::laugh:

[TZ350]

Maybe I could resurrect TZ's plenum idea, mount the carb to the frame and use a flexible hose between it and the plenum.

Pumper Carb maybe? ....

327552 Tillotson HL360A (24mm venturi).

Made 28 rwhp with this puppy, no bell mouth and bolted hard to the crankcase. Vibration does not seem to affect them.

[adegnes]

Pumper Carb maybe? ....

327552 Tillotson HL360A (24mm venturi).

Made 28 rwhp with this puppy, no bell mouth and bolted hard to the crankcase. Vibration does not seem to affect them.

It's been on my mind more than one time...
With a new valve cover it would give me a shorter intake too.
I'll have to sleep on it.
I know the Zundap rvrt crew are going pumper now, after similar issues with fuel foaming.

http://www.deraceheldenvanweleer.nl/index.php?topic=1604.new;topicseen#new

[oldjohnno]

Getting the vibration down to a reasonable level shouldn't be too difficult with a small engine. The one I had trouble with had an 86mm bore, though it only revved to 8500. To find a workable BF in a reasonable time (and without stripping the engine countless times) I overbalanced the crank to nearly 70% then experimented with small external bobweights that could be changed quickly that were attached to the flywheel and primary drive end. I don't know why but the carburation seemed to be upset more by overbalance than underbalance, even though underbalance felt worse through the 'bars.

The best results came from 60 to 65% so the crank was removed one last time and balanced to that figure. But the small amount of external weight didn't seem to cause any problems at all and I'm sure I could have left it that way. Could be difficult to attach weight to the drive end with a disc valve though.

[husaberg]

Getting the vibration down to a reasonable level shouldn't be too difficult with a small engine. The one I had trouble with had an 86mm bore, though it only revved to 8500. To find a workable BF in a reasonable time (and without stripping the engine countless times) I overbalanced the crank to nearly 70% then experimented with small external bobweights that could be changed quickly that were attached to the flywheel and primary drive end. I don't know why but the carburation seemed to be upset more by overbalance than underbalance, even though underbalance felt worse through the 'bars.

The best results came from 60 to 65% so the crank was removed one last time and balanced to that figure. But the small amount of external weight didn't seem to cause any problems at all and I'm sure I could have left it that way. Could be difficult to attach weight to the drive end with a disc valve though.
hose clip.............

This can be offset by creating an opposite force in the flywheel,as I tested this by clamping a hose clip onto the ignition,with the screw positioned 1/2 way opposite between the two pistons at TDC.
But this "fix" creates a huge rotating out of balance force on one end of the crank - and the RZ case has enough trouble maintaining main bearing crush on a balanced assembly, without pounding it to death running an out of balance flywheel.
The carbs and bars vibrate enough to froth the fuel without soft manifolds - so the idea was dropped ( on my head).

[oldjohnno]

I found that maintaining an equal amount of bobweight at each end of the crank was very important - if I got lazy and fudged it by taking a few grams off one end only the thing would vibrate disproportionally. You have to match the weights very closely end-to-end. I guess if for some reason - like a disc valve - you couldn't avoid some amount of unbalance at one end of the crank then you'd have to mirror that condition at the other end and balance the crank with the disc and flywheel fitted.

[adegnes]

The next time I have it apart I will do some serious balancing with disc and variator on the crank.

Before I give up and buy a Tillotson(can't afford one atm anyways...) I'll try extending the main jet with a short piece of tubing into a "well" with foam. Wish me luck!

[husaberg]

The next time I have it apart I will do some serious balancing with disc and variator on the crank.

Before I give up and buy a Tillotson(can't afford one atm anyways...) I'll try extending the main jet with a short piece of tubing into a "well" with foam. Wish me luck!
Every second chainsaw has one of those Tillotsons.
You are going to make the well deeper though as well for the PWK?
If you can find a suitable thread tap you could make one out of a brass pipe fitting?
Something like this?
https://thunderproducts.com/shop/deep-well-float-bowl-nuts/

the fcr has the same thread it seems as the PWK (note the holes)
http://www.frankmxparts.com/WebRoot/StoreNL/Shops/62910900/55F0/459A/A0AF/9794/D7D3/C0A8/2AB8/794F/mino-orange-float-bowl-drain-bolt-nut-with-o-ring-keihin-fcr-mx-32-37-39-40-41-flatslide-carburetor-frank-mxparts-02.jpg

[adegnes]

You are going to make the well deeper though as well?

Yep, will drill out a spare "bottom screw" and epoxy an extension pipe to it, fill it with foam and run a piece of tubing down to the bottom of it. If it works I'll make something proper.

Just the small piece of foam around the main jet didn't help much. I tested that, did some jet changes and played with the ignition timing a bit today. Had planned for a lot more testing, but was cut short by angry neighbors. (video is uploading)
It responds to jetting at low rpm, but as Frits mentioned, when the fuel starts boiling it's all over the place.
Seemed to rev a bit better with a 135main vs 115, but when thats all from such a great jet change it's no point in trying to tune it. EGT remained the same.

Crossing fingers for the well to fix it.

[TZ350]

327555

learnt a lot yesterday watching Speedpro working with the Ecotrons self learn feature of their EFI software. Using his dyno chassis load break Speedpro managed to hold the rpm/tps steady on my bike at enough points to give the software enough time to auto tune a number of points on the fuel Map. Now I have to sit down and analyse what it means.