52 Mk 11 the start

[Rick 52]

216754
Brakes stripped and cleaned,forks stripped and all ready for new seals,rear sets hammered straight and one needs welding up,frame ready for new engine mount to be welded on ,TS ER 6speed engine at the builder for CR85 ignition ,new rod piston and bearings ,O-ring the head sort out compression and clean up the ports .Lots of work to do but It will have to be ready for testing before Taupo .

[Dutchee]

Great Rick, just what we need - you, Tim or Gav faster up here. Next you'll be telling us Tim's lining up another bucket as well.
You'll be best testing it at the two hour in November, in preparation for Taupo.
M

[Ned Kelly]

Good to see you are getting into the RS new bike project Rick. So much to do before Taupo. Same old story. Our water cooled GP100 is nearly ready for reassembly. Major parts are done
Hope fully with all going well 25+ HP. Fingers crossed.

[Pumba]

Lots of work to do but It will have to be ready for testing before Taupo .

Be carful making promises like that, they might come back to haunt you:shifty:

[Henk]

I must say I'm a little disapointed. Abandoning the true sprirt of bucket racing and going from an FXR to a one off smelly two stroke with real power and handling. Shame on you.
How long before Will is circulating in the B grade with your cast off old bike?

Seriously though, look forward to being made to look even more stupid when you get this up and running.

[Buckets4Me]

I must say I'm a little disapointed. Abandoning the true sprirt of bucket racing and going from an FXR to a one off smelly two stroke with real power and handling. Shame on you.
How long before Will is circulating in the B grade with your cast off old bike?

Seriously though, look forward to being made to look even more stupid when you get this up and running.

you got that backwards
will is small and light so need a bike his size
rick will be lucky to do the test riding

[Rick 52]

you got that backwards
will is small and light so need a bike his size
rick will be lucky to do the test riding

Haha Will has problems with anything to do with Cr85 they spit him off evry time !
He is 13 in Febuary and the FXR will be sold to get some money back I think we will sort him a CB 100 for F5 as 2 strokes are not his thing
Used paint stripper to remove 8 layers of paint from the tank today it has some dents but I think I will keep it ally as it is a work of art (I like polishing ally )

[Henk]

(I like polishing ally )

Good, you'll be doing it every time it rains :yes:

[Buckets4Me]

Used paint stripper to remove 8 layers of paint from the tank today it has some dents but I think I will keep it ally as it is a work of art (I like polishing ally )

copy cat 216820


the bike will lok like mine
ps may have a spare black fairing for you to :)


have you given up on the gp
i think i have a spare chamber muffler for that if you havent

if you have can I have and how much :p (could be my next engine with a watercooled head )
216819dont forget that the radiator mount needs beafing up

[F5 Dave]

I must say I'm a little disapointed. Abandoning the true sprirt of bucket racing and going from an FXR to a one off smelly two stroke . . ..

Rubbish, FXRs are a lazy option. Good on ya Rick.

Will you have clearance for the carb vs shock? (or the rest of the engine to the frame for that matter).

[bucketracer]

.........TS ER 6speed engine at the builder for CR85 ignition ,new rod piston and bearings ,O-ring the head sort out compression and clean up the ports.........

TS-ER125 sounds a good option, If you arn't going to use that Suzuki GP125 engine I would be keen to buy it from you and the pipe too if your not planing on using that either.

[TZ350]

216754
........will have to be ready for testing before Taupo.....

Great to see another Bucket weapon taking shape..........

After breaking the alloy front mount at the BOB Chambers made this metal mount up and NedKelly riveted it on, if they were doing it again they said they would glue and rivet it.

[Rick 52]

The engine carb is very tight but it will go.
I am having the frame welded and beefed up around the rad mount next week ..,I'm not sure if to sell the GP engine yet lets see how the TS go's... The forks have been cleaned out and new seals tonight but I'm not sure what air gap to leave' I used 130mm I think its a bit big but they feel great ,I used 10w fork oi...,I orderd the tail unit from the guy in CHCH $190 deleived not cheep but it should be good.

[TZ350]

......I'm not sure if to sell the GP engine yet lets see how the TS go's....

If you do decide to sell the GP engine and pipe and no other Bucketeer holds their hand up, we would be pleased to get them.

[F5 Dave]

Rivets are great & that would be a fine & worthy mount for the radiator.

But they aren't so keen on vibration. I'd be looking at how you can bolt that on. That piece of the frame on the bottom isn't the best for that application. I'd be forming a plan B.

[F5 Dave]

Rivets are great & that would be a fine & worthy mount for the radiator.

But they aren't so keen on vibration. I'd be looking at how you can bolt that on. That cast piece of the frame on the bottom isn't the best for that application. I'd be forming a plan B.

[TZ350]

Rivets are great.........But they aren't so keen on vibration. I'd be looking at how you can bolt that on.......I'd be forming a plan B.

Yes that’s why we are looking at gluing it, with the large contact area a good epoxy glue that stays slightly malleable after curing is an option, with the rivets there to just to hold it all in place while the glue goes of.

[richban]

Nice work Rick. Seams there are a few projects in the mix for Taupo. Can't wait better get my entry in.

[Rick 52]

Another weekend in the garage and all is going well The tank has a low fuel tap and it was going to hit the engine so its been cut and blocked off with 8mm ally drill and tapped for a fitting .The frame has been welded with new brackets for the front engine mount ,we have an ally welder at work but had never been used for ally just stick I got it going but the water cooled torch had a blockage and had to be used in short bursts and its been about 10yrs since I last welded ally but its gone good.217200217201217199217198217197
I made a spacer for the front brake caliper its all on and works good but bleeding was a bitch front and back ,The forks feel great after new seals and oil ,Ive ordered a new seat unit from ChCh and I won a set of fairings on Trade me so it only the engine to get back and fit then rear sprocket

[F5 Dave]

Now that looks like a substancial mount, if not winning any welding awards should be well up to it. Those tanks can be 'altered' with a rubber mallet if they hit spark caps etc, they seem to be quite nice malleable ally.

[bucketracer]

.

Good work, that bike is starting to look truly dangerous.........:soon:

[gav]

Now that looks like a substancial mount, if not winning any welding awards should be well up to it. Those tanks can be 'altered' with a rubber mallet if they hit spark caps etc, they seem to be quite nice malleable ally.
Thats not a front mount, THIS is a front mount!
http://www.fxr150.co.nz/discussion/download/file.php?id=720&mode=view

[TZ350]

Hmmmm Gav that's got me re-thinking the way we did ours now..........

[gav]

http://www.fxr150.co.nz/discussion/viewtopic.php?f=6&t=229
All the details on the bike are right here.

[TZ350]

Read through the thread, thoroughly enjoyed following the build. The front mount has been the week point on our bike and didn't last the 55min, yours looks good.........

[F5 Dave]

Yeah Bren had already sent us those pics. I use the same RS mounts on my 50 & have moved them on my old aircooled 125 & now my 100, but you have to be careful on the MB engines as the front mount isn't really an engine mount & can crack. dumb huh?

[speedpro]

Instead of extending the mounts on mine i have cut the extensions off and the mounts are direct to the bracing on the frame. I then have a steel bracket that goes under the standard head bolts which the engine mounting bolt goes through.

[TZ350]

Speedpro any chance of a pic......... please

[Buckets4Me]

Speedpro any chance of a pic......... please

217678 217677 217676



sorry Rick for hijacking this threat

[speedpro]

that's my FZR chassis. you can see in this how something can be placed under the head bolts though. The RS125 chassis version is a lot smaller and has triangular plates sticking up with a tube through extending out each side. when finished it will line up with the engine mounts and the bolt will slide through from one side to the other.

[Rick 52]

Very cool ,Its good to see other ways of mounting .........Engines.
Its the rear mount I'm not sure about yet and with my engine away I will have to see when it gets back .I picked the fairings up on Thursday Carl should I bring them to the next meeting ? Gearing any ideas fellas ....I will have to buy a blank rear but I can only find a 48 tooth 428 pitch ...so 12-48 what do you think ?this is the same as my FXR then I use a 14 front for Taupo.

[speedpro]

I had a 52T rear sprocket I used on the kart tracks and a 48T for big tracks. I also had 12-17T fronts so had it pretty covered. 12-48 will do to get started for sure. You will end up changing gearing to avoid the 3rd to 4th change exiting corners

[speedpro]

I just checked and I have a 428 33T sprocket I don't need any more. It's thinned and lightened and machined to fit an RG50 sprocket carrier. You're welcome to it if it's any use.

[Rick 52]

Cheers Mike ,I think the centre hole has to be 42mm for the Rs,Are you going to the next meeting ?

[Buckets4Me]

Carl should I bring them to the next meeting ? Gearing any ideas fellas ....I will have to buy a blank rear but I can only find a 48 tooth 428 pitch ...so 12-48 what do you think ?this is the same as my FXR then I use a 14 front for Taupo.

yep next meeting pay you then ?
unless I see you at touch or something

ask Dad about where to get sprokets from
you will have to machine them up but it's not to hard and they are easy to change after that

[TZ350]

Very cool ,Its good to see other ways of mounting .........Engines. Its the rear mount I'm not sure about yet......

Team ESE's approch to the rear engine mount using the original RS mounts on NedKellys bike.

[Rick 52]

Its running !! Lots of work done but the carb keeps falling off and the clutch slips ...
I have changed the plates and the oil but still it slips ..plenty of free play I'm over it for today so I'm going for a swim

[Buckets4Me]

Thats starting to look good
now I understand why that tail on the fxr never got painted and looks so ugly :)

[Buckets4Me]

:woohoo::woohoo::woohoo::woohoo::woohoo::woohoo::w oohoo::woohoo::woohoo::woohoo::woohoo::woohoo::woo hoo::woohoo::woohoo::woohoo::woohoo::woohoo::wooho o::woohoo:

and another 2 stroke comes alive

[F5 Dave]

Wind the springs in on the clutch. Getting the pins through will require some skill, make a spring puller.

That manifold will be a source of constant problems. Try convert to a plate with a bolt on rubber manifold. A GP125 rubber works well on 24mm carbs.

[Rick 52]

Cheers Dave I will try the springs they are a bastard to get them in ..
The carb is a 28mm flat slide and the manifold is 24mm plus it has to be longer than I would have liked because the carb hits the rear shock mount..your right its going to be a problem.

[TZ350]

.

Its great to see another special being built.

Chambers recons, old 2-Strokes never die they just go faster..........

[jasonu]

Cheers Dave I will try the springs they are a bastard to get them in ..
The carb is a 28mm flat slide and the manifold is 24mm plus it has to be longer than I would have liked because the carb hits the rear shock mount..your right its going to be a problem.

Can you notch out then weld the cross member for more clearence or maybe remove it altogether and weld it back in a nearby location?
That long garden hose 'manifold' you have made will definitely cost HP and looks really shitty too, do something better.

[F5 Dave]

Think my 28mm carbs I run on the 50 run with an X7 inlet manifold. You can cut off the old one & weld a plate to the barrel. The rubber manifold bolts to this. You only need a bit of weld & fill the gaps with Devcon or JB weld. Do it on a slight angle , say to the left & smooth a nice curve with Devcon to get the carb out of the way to the side a bit. Should be less of a compromise. A PWK flatslide may be smaller than a Mikuni.

[jasonu]

Think my 28mm carbs I run on the 50 run with an X7 inlet manifold. You can cut off the old one & weld a plate to the barrel. The rubber manifold bolts to this. You only need a bit of weld & fill the gaps with Devcon or JB weld. Do it on a slight angle , say to the left & smooth a nice curve with Devcon to get the carb out of the way to the side a bit. Should be less of a compromise. A PWK flatslide may be smaller than a Mikuni.

Or find an angled manifold, bound to be a bike out there that came with one.

[TZ350]

I don't think it will be too long before the two strokers disappear............

I was starting to think so too, as FXR's are so easy, but now, with Speedpros MB100 making near 30rwhp, I think 2-Strokes will survive as the playthings of the die hard stroker fans :D and dedicated tuners :blink: ......

[jasonu]

I was starting to think so too, as FXR's are so easy, but now, with Speedpros MB100 making near 30rwhp, I think 2-Strokes will survive as the playthings of the die hard stroker fans :D and dedicated tuners :blink: ......

... and REAL MEN...

[Rick 52]

Pulled the clutch down and found the shaft was stiff to turn ,got the seal out and the shaft had a rough spot on it ..Cleaned it its now much better.
The spring were wound all the way in so I checked them next too the TS clutch springs they are much shorter and red so they must be better :innocent: Its too late to test now fingers crossed ...The carb rubber has now been epoxy onto the spigot for now ,I have to test at the track this weekend its the last time before Taupo.

[F5 Dave]

Yeah rubber always sticks well to epoxy. . . Fix it or your GP will be a pushfest.

[jasonu]

Is this a 100cc or a 125cc motor?

[TZ350]

I have to test at the track this weekend its the last time before Taupo.

I see photos :- http://www.flickr.com/photos/hz13/sets/72157625498729897/?page=2

Michelle got some good photos. So how did it go? Whats it like to ride................

[Rick 52]

Its a TF 125 ,It goes well plenty of bottom end and pulls all the way .The handling feels so light after the FXR it tips in so easy ,I only got a few laps in the dry and was taking it slowly but first impressions are good ..Got it on the scales and with half a tank it is ..........73kg brilliant its 30kg lighter than the FXR .:woohoo:
I need to shorten the clutch cable and sort little bits but I'm pleased so far ...lets see what falls off or breaks today !!!:shutup:

[jasonu]

Its a TF 125 ,It goes well plenty of bottom end...

Your 28mm carb is not within the rules. You are allowed 24mm max on a 125 aircooled 2 stroke. Your 24mm runner does not make a bigger than 24mm carb legal. Better to find out now and fix it than to get protested at the track. I am surprised no one else has pointed this out. I even saw a pic of Green looking at it in the pix from Mt Welli yesterday.
Nice looking bike though.

[Buckets4Me]

Your 28mm carb is not within the rules. You are allowed 24mm max on a 125 aircooled 2 stroke. Your 24mm runner does not make a bigger than 24mm carb legal. Better to find out now and fix it than to get protested at the track. I am surprised no one else has pointed this out. I even saw a pic of Green looking at it in the pix from Mt Welli yesterday.
Nice looking bike though.


thats because Green was only going to protest when and if Rick beat him :facepalm: (best money you could spend)

Go Talk to TZ about modifying the carb to make it legal and still flow well :drinkup:

[jasonu]

Go Talk to TZ about modifying the carb to make it legal and still flow well :drinkup:[/QUOTE]

Do tell TZ, how is this done?

[speedpro]

Me and TZ were chatting about this the other day. The kart guys have carb rules as well but they specify where in the carb the measurement is made. Bucket rules don't, so the crafty among us have installed a part that has a 24mm diameter in the carb past the metering venturi. This part, due to it's design, flows more than a 24mm carb. This part is installed in carbs larger than 24mm. If it's installed as part of the carb then technically the bucket rule as written has been complied with.

[kel]

[QUOTE=jasonu;1129936060]Your 28mm carb is not within the rules. You are allowed 24mm max on a 125 aircooled 2 stroke.

Yeah I think if Rick proves unstoppable we might have to protest :innocent:, problem is 24-2-4 is worded "equivalent to a single 24mm" as such any old restriction to 24mm in the carb outlet complies with the rule.

[jasonu]

Me and TZ were chatting about this the other day. The kart guys have carb rules as well but they specify where in the carb the measurement is made. Bucket rules don't, so the crafty among us have installed a part that has a 24mm diameter in the carb past the metering venturi. This part, due to it's design, flows more than a 24mm carb. This part is installed in carbs larger than 24mm. If it's installed as part of the carb then technically the bucket rule as written has been complied with.

Who (someone whos decision carries some weight) said if the part installed as part of the carb it complies with the rules? Has anybody tested this modification with an actual protest? Has this been brought to the attention of MNZ scrutineering or technicial staff that might, in the future, be involved with any protest? What is John Connors opinion? If the point of measurement is not specified, where exactly would an official get his measurement from? What is stopping the official from takeing the measurement from another part of the carb that is still bigger than the allowed 24mm and disqualifing the bike?
To me, this sounds like some sort of tricky loop hole that could result in a bike being deemed illegal as the official can (it seams) take a measurement from anywhere, and also some might say it is not within the 'spirit' of the rule as when you (Mike) put this rule to MNZ I know the intent was for a 24mm or equalivient carb and this was not forseen.
I don't like it and think someone should look at modding the rule as to exactly where the measurement is taken as in the karting rule you mentioned.
I for one would protest it in a championship or title situation (that is if I ever get myself into that situation which is highly unlikely).

Is anyone else using this part? How about posting a picture or two, I would really like to see what you have done.

[ac3_snow]

F4 2 stroke engines over 104cc are restricted to carburation equivalent to a single 24mm carburettor

The rules do state that it is restricted to the equivalent of a 24mm carb. So placing an insert of 24mm into a larger carb would not then be equivilent to a 24mm carb, because as you say speedpro it still flows more than an actual 24mm carb would.

I see what you are saying that by placing the insert in there, at least some of it has a diameter of 24mm but I don't see it to then be the equivalent of a 24mm carb. To be the equivalent of, it would need to have a 24mm sleeve put in right through the carb? Or at least on the intake side before the slide?

That at least is my own humble, unexperienced opinion. Be interesting to hear an official take on it. (or as official as buckets can get)

[TZ350]

Has anybody tested this modification with an actual protest? Has this been brought to the attention of MNZ scrutineering or technicial staff that might, in the future, be involved with any protest? What is John Connors opinion? If the point of measurement is not specified, where exactly would an official get his measurement from?

The convention is that Carbs are sized at the major venture, carbs can have more than one venture, in fact its common for carbs to have ventures within or upstream of other bigger venturies, take a look at a Holly or Rochestor or even the carb on an older Jap car.

Not all carbs of the same size flow the same amount of air, we have checked quite a few with our simple flow bench and found ways to improve them.

Are Buckets to be limited to unmodified store brought 24mm motorcycle carbs and ideas?

Inventiveness is within the spirit of Bucket racing, and this carb mod this has been run past JC and he was OK with it.

Maybe he was more relaxed about it as all the details and theory have been posted on the ESE thread so anyone can copy it if they make the effort.

I will dig up some of the posts...........

[jasonu]

Carbs are allways sized at the venturie, for a carb to work the venturie and fuel metering section don't have to be at the same place, its just cheeper to make them that way.

Not all carbs of the same size flow the same amount of air, we have checked quite a few with our simple flow bench and found ways to improve them.

Inventiveness is within the spirit of Bucket racing, and this carb mod this has been run past JC and he was OK with it.

Maybe he was more relaxed about it as all the details and theory have been posted on the ESE thread so anyone can copy it if they make the effort.

I will dig up some of the posts...........

With all respect to JC, he does a hell of a job, are you sure it is his call to make? If it was run past the appropriate MNZ official, one who might deal with a protest, and OK'd then that would be that I guess. I agree with inventiveness being a big part of bucketting but I see this as a loop hole that should be closed. I do not think you should be limited to a 24mm stock store brought carb, just one that is equivalent to a single 24mm carburettor, maybe a smaller carb that has been D bored. maybe twin 9mm carbs (good luck getting that to work) for example , as long as the 24mm thing is adherred to. That sort of thing IMO is inventiveness. What I don't want to see is someone putting a great deal of time, work and money(?) into developing a motor around this mod and then finding out it is not allowed. I for one would get a final answer from someone in the position to make the call first. Frankly, if someone wants to run a bigger carb, then build a 100cc motor.

Looking forward to seeing your old posts about this, pix too hopefully.

[TZ350]

With all respect to JC, he does a hell of a job, are you sure it is his call to make?

I for one would get a final answer from someone in the position to make the call first.

Looking forward to seeing your old posts about this, pix too hopefully.

True JC, can't speak for MNZ but I was being upfront with him and you asked.

Good advice, if your one of those at the pointy end then it would be good idea to get an official MNZ opinion.

Yes there are pic's, there are over 1200 pic's on the ESE thread, "Thread Tools" near the top of the page makes it easier to look through them.

I will get onto the finding the Posts now, back soon.

[TZ350]

Looking forward to seeing your old posts about this, pix too hopefully.

There were a number of posts about this, found three.

A carb is sized by measuring the major venturi, common motorcycle carbs have the metering orifice and air control (usually a slide) and a single venture but there are other ways of controlling air flow, fuel metering and fuel atomisation.

Some carbs have mutiple venturis and even venturies within venturis.

So should the Bucket 24mm carb rule also limit us to simple single venturi unmodified 24mm store brought motorcycle carbs and thinking, should a Bucket carb have to follow commercial motorcycle convention and limitations?……………..

Fuel metering and the major venturi of a carb do not have to be in the same place.

For a performance carb it makes sense to have the most restrictive metering bits separate from the highest flow section.

If fuel metering is upstream of a venture smaller than the metering section then fuel atomisation is greatly improved by the fuel droplets bursting as they pass through the high velocity low pressure area of the down stream venture.


Flow tested some carbs today. Thomas made up a manometer, which proved to be very effective at measuring flow through the carburettors.


The current challenge is to get more air into the engine through the 24mm carburetor. A carburetor is basically a simple venture.

Picture-01 of a traditional venture (A) and a low loss flow tube (B) where the maximum pressure recovery (flow) occurs when D2/D1 is between 0.6 to 0.7.


Here are pictures of the actual carbs themselves.

Pic-01 and 02 the 28mm Keihin with a permanently fitted 24mm choke.

Pic-03 and 04 The taper bored power jetted OKO (Keihin Copy) 24mm at the bell mouth 28mm at the engine side.

I think this inventiveness is in the spirit of buckets but if anyone thinks its not within the rules and can explain why please tell me now before I hit the track at Taupo.

Our venturi inserts are as much about improved fuel atomisation and driveability as air flow, all important things in a 2-Stroke.

Click on the Quotes to see the full text and pictures……….

[ac3_snow]

.
I think Chambers is going with a conventional 24 first, then when the bugs in the rest of the new bike are ironed out he might try the 38/24.

But yes, 38/24 feeding both cylinders. We have been successful with a 28/24 combo on the GP125 and now have a 38/24 that shows real promise on the flow rig.

One of the problems I can see, is low signal strength at the main jet. Our 28/24 run conventualy uses a 130 main. Keihin 38’s on 125 MX’s run 180-190 mains std.

So I expect that on a 38/24, the main will need to be even bigger. Because of the reduced signal from lower airflow passing through the 38mm metering section at full throttle due to the more restrictive 24mm venturi section of the carb down stream.

My guess is 200+ for the main on our 125's using a 38/24 venturi carb...................

Also we figure, if you can't drop a 24mm ball brg through a carb with a circular throat then the cross sectional throat area is equivalent to or less than a carb of 24mm and so satisfies the 125 2-Stroke carb rule.

The beauty of the 38/24 combo seems to be that the airflow in the 38 section gets straightened up before entering the 24mm venturi allowing a higher flow rate in the venturi area.

The details and pictures are in earlier posts. From memory, if the venturi is 60-70% of the pipe (carb) diameter then there is a 94-98% pressure recovery (air flow) down stream for Reynolds (gas velocity) numbers less than 0.5.

So you can see that its possible to make a 38/24mm combo carb that flows like a conventional 34mm. But wether it works on the track we wont know untill we get one of the new bikes going.

Remember you heard about this idea of 38/24 and 28/24 carbs from Team ESE first..............

Ohh yea, I found this one on page 147 of the ESE thread. Very interesting, the way you describe it makes alot of sense, I now retract most of my previous statement after reading your posts.
So how many people are currently running this 24mm venturi system with an 'oversized' carb?

[TZ350]

So how many people are currently running this 24mm venturi system with an 'oversized' carb?

Up here, only me at the moment that I know of, and there is someone in CHCH with one I think.

So there is no unfair advantage, anyone can follow the links like you did and find out everything they need to know to make one for themselves.

Anyone can have one of these carbs if they make the effort.

[jasonu]

Up here, only me at the moment that I know of, and there is someone in CHCH with one I think.

So Rick is running a straight 28mm and therefore illegal carb.

I am still unsure of exactly what you have done. Does your insert go right through the carb and does it measure no more than 24mm (or equivalent) where the slide shuts off the fuel/air delivery? If you buy Mik or Keihin carb that is specified 24mm you will find that measurement at that same place ie in the middle of the venturi where the slide is.

[TZ350]

So Rick is running a straight 28mm and therefore illegal carb.

I am still unsure of exactly what you have done. Does your insert go right through the carb

I don't know about Ricks setup, its new and I havn't seen it yet, didn't know he had a 28 untill you pointed it out. The info about how to improve these carbs has been around on the ESE thread for a year or so, he could have made 28/24 like mine ...........


Here are pictures of the actual carbs themselves.

Pic-01 and 02 the 28mm Keihin with a permanently fitted 24mm choke.

Internaly the high velocity atomisation choke area looks like the shaded part in the first picture and the tail of it can be seen sticking out of the carb in the second picture.

[jasonu]

No not Rick...........



Internaly the high velocity atomisation choke area looks like the shaded part in the first picture and the tail of it can be seen sticking out of the carb in the second picture.


The whole thing looks grey to me. I think the rule should be rewritten and include the point where the measurement will be taken and that point should be where the slide cuts through the venturi. ie if you were to take a felt pen and trace out the opening onto the closed slide, that area should be the 24mm or equivalent.
I know you said in some cases the venturi is not always in the same place as the slide, that is more of an automotive thing where there is a butterfly instead of a slide and neither of us can recall seeing a 2 stroke carb with the slide in a different location to the venturi except for kart carbs which have butterfly valves.

[TZ350]

So Ricks bike is illegal due to the 'normal' 28mm carb???


I don't know about Ricks setup, its new and I havn't seen it yet, didn't know he had a 28 untill you pointed it out. The info about how to make an improved carb has been around on the ESE thread for a year or so, he could have made 28/24 like mine ...........


I think the rule should be rewritten and include the point where the measurement will be taken and that point should be where the slide cuts through the venturi. ie if you were to take a felt pen and trace out the opening onto the closed slide, that area should be the 24mm or equivalent.

It would have to be some sort of good definition like that.......

The Dutch specify a (24mm?) diameter ball, if it doesn't drop through its legal, the smart boys machine the bore oval for extra area.


I know you said in some cases the venturi is not always in the same place as the slide, that is more of an automotive thing where there is a butterfly instead of a slide and neither of us can recall seeing a 2 stroke carb with the slide in a different location to the venturi except for kart carbs which have butterfly valves.

Does a Bucket carb have to follow convention....... is that what Buckiting is about, following convention.


neither of us can recall seeing a 2 stroke carb with the slide in a different location to the venturi except for kart carbs which have butterfly valves.

I think the Karts specify a max venturi diameter and as a matter of conveniance the fuel discharge nozzels are placed there and the butterfly is in a larger diameter area.

I will see If I can find a picture.

[TZ350]

I think the rule should be rewritten and include the point where the measurement will be taken and that point should be where the slide cuts through the venturi. ie if you were to take a felt pen and trace out the opening onto the closed slide, that area should be the 24mm or equivalent.

The rules say, "restricted to carburation equivalent to a single 24mm carburettor" so there is no restriction on make or style, the carburettor could be anything, even some new fangled approch that you cobbled together for yourself from old taps and the kitchen sink and something else from the laundry.......

So I propose a definition.

A light is shined through the open carb and the smallest cross sectional area seen must not exceed a 24mm Dia equivalent.

I know its not conventional but is there anything wrong with that for a definition that ensures compliance with the rules.......

[Rick 52]

226683

The 28mm carb would not fit with the time I have to play with so this is the carb I am running with ,And it goes great today was tricky in the wet but lots of good power with magic feeling ..Very pleased with my legal bucket thank you ..

[TZ350]

I hope that tape measure has been calibrated recently........... :bleh:

[rwh]

So I propose a definition.

A light is shined through the open carb and the smallest cross sectional area seen must not exceed a 24mm Dia equivalent.

You'd get away with a really big carb if it was curved ...

But it seems reasonable to me (as someone with no involvement whatsoever in racing) to simply say "all the air must at some point go through an orifice of max 452.4 square mm, at or below atmospheric pressure"

Then you can have all the tricky designs you like - with the slight problem that it might be difficult to measure.

Oh, and I guess you could do some tricky stuff by having the restriction on the intake to a really big airbox ...

edit: or by having a super/turbocharger downstream of the restriction

Richard

[TZ350]

You'd get away with a really big carb if it was curved ...

Good point, I hadn't thought of that.......


Oh, and I guess you could do some tricky stuff by having the restriction on the intake to a really big airbox ...

Checkout the plenum idea on the ESE thread.......

Small carb, big plenum, motor sucks directly from the plenum.

[RMS eng]

The rules say, "restricted to carburation equivalent to a single 24mm carburettor" so there is no restriction on make or style, the carburettor could be anything, even some new fangled approch that you cobbled together for yourself from old taps and the kitchen sink and something else from the laundry.......

So I propose a definition.

A light is shined through the open carb and the smallest cross sectional area seen must not exceed a 24mm Dia equivalent.

I know its not conventional but is there anything wrong with that for a definition that ensures compliance with the rules.......

24mm carb for a 125 two stroke needs to be measured 24mm over the area where the slide runs,which is where the air fuel mix is controlled which makes it a 24mm carb,running a 28-30mm carb with a 24mm spacer at one end is still a 28-30mm carb,unless you press in some kind of 24mm sleeve where the slide shuts off air coming into the carb.a 28mm carb is 35% bigger in area than a 24mm carb and putting a small 24mm restricter at the inlet end of a 28mm carb won't do much to stop this carb working like a STD 28mm carb at most of the rev range on a 125 2 stroke.if any one wants to use a kart type carb good on them but it must be the eqvivalent to a 24mm motorcycle carb,eg KT100 carb for karting must measrure venturi 24.13mm throttle bore 25.65mm[bell book].when Jason ,M green and myself made up these rule we did our home work,i still have the books we got the info from,and the 24mm carb rule was set,as i new a 1993 TZR 125 with a 28mm carb made 24,5hp at 9700rpm and 15hp at 8000rpm stock.

[kel]

24mm carb for a 125 two stroke needs to be measured 24mm over the area where the slide runs.

But thats not what the rule states.
Me thinks if you want to argue with TZ's sensible proposal/explanation re measuring that you may have to ammend the rules. I can think of a couple more rule changes to slow down those pesky 2 strokes. :corn:

[jasonu]

But thats not what the rule states.
Me thinks if you want to argue with TZ's sensible proposal/explanation re measuring that you may have to ammend the rules. I can think of a couple more rule changes to slow down those pesky 2 strokes. :corn:

That is the point, the rules do not specify WHERE the measurement should be taken.
It seems to me that if a manufacturer like Mikuni or Keihin sell you a (for instance) 24mm carb, you will find the 24mm measurement comes from across the venturi where the slide closes off the fuel/air mixture ie a 24mm carb, not a 28mm venturi carb with some sort of 24mm restriction somewhere else.
This issue needs to be addressed by the appropriate MNZ technicial staff and a ruleing should be made ASAP as to where or how the measurement will be taken. It should be done before someone using this idea, starts winning and is then possibly protested and DQ'd. If you want to make a carb out of a garden tap and some sticks or use a kart carb then it would be up to the user to prove it is within the 'equivalent to 24mm' rule.
As for slowing down the pesky 2 strokes, the aircooled 125's have a 25% cc advantage and the coal burners have a 50% cc advantage. Hell, you can buy a stock FXR and be competative just by fitting slicks, a pipe and carb. To get the same level of competativeness out of a 100cc 2 stroke...

I for one am all for inventiveness but I think this is more of an unforseen loophole that needs to be fixed before someone crys.

[kel]

Hell, you can buy a stock FXR and be competative just by fitting slicks, a pipe and carb.

Yeah just dropped mine into the local bike shop ... :bleh:

[jasonu]

What about no carb restriction on aircooled 125's and at the same time increase 100cc watercooled to 125cc with an 'max size equivalent to' 32mm carb measured anywhere you want?
I've got a few RG500 cylinders and they bolt right on. 35hp here we come YEEHAA!!!

[TZ350]

What about no carb restriction on aircooled 125's and at the same time increase 100cc watercooled to 125cc with an 'max size equivalent to' 32mm carb measured anywhere you want?
I've got a few RG500 cylinders and they bolt right on. 35hp here we come YEEHAA!!!

Actually I like the idea......... no carb restriction on aircooled 125's and 125 water cooled's restricted to 24mm equivelent measured at the front of the slide. The front makes them easer to check.

Water cooled 100's as they were, unrestricted.

[TZ350]

This issue needs to be addressed by the appropriate MNZ technicial staff and a ruleing........

Sounds like a ruling is required...............

While they are at it, it might be best if they also ban hand made carbs.

As I already have plans for one in the traditional style that would meet the proposed measuring spec that I expect will flow just as well as my current modified 28/24 or maybe better. Take a look at a production carb and you can see its badly compromised for the ease of production.............

Also if they don't make it a requirement that it has to be a traditional slide carb salvaged from some old shitter motor bike, then I also have ideas (tested on a car) about using a double veriable venturi and no slide at all, so tell me where would you measure that..........

[jasonu]

Sounds like a ruling is required...............
You are right, a ruleing needs to be made and the rule needs to be re written.

While they are at it, it might be best if they also ban hand made carbs.
Na mate, if you want to make your own carb out of lego I would be OK with it as long as it is within the rules as I have stated several times in this thread.

As I already have plans for one in the traditional style that would meet the proposed measuring spec that I expect will flow just as well as my current modified 28/24 or maybe better. Take a look at a production carb and you can see its badly compromised for the ease of production.............

Also if they don't make it a requirement that it has to be a traditional slide carb salvaged from some old shitter motor bike, then I also have ideas (tested on a car) about using a double veriable venturi and no slide at all, so tell me where would you measure that..........
It would be up to you to prove its legality.

[Yow Ling]

Just push a turd through the carb / inlet duct , if it comes out more than the area of a 24mm carb it would be illegal. Whoever wrote the rule for 24mm carb equivelent wasnt thinking that it would ever be challenged and never wrote exactly what they were thinking or meaning.

[bucketracer]

It would be up to you to prove its legality.

The rules talk about carburation equiveilent to........ not, it must be a traditional slide carb...... and it has to be equivelent to the area of (didn't say, a traditional carb measured traditionaly) 24mm carb ...........


Whoever wrote the rule for 24mm carb equivelent wasnt thinking that it would ever be challenged.

Or that some would be smart enough to think of a way to do it.


Just push a turd through the carb / inlet duct , if it comes out more than the area of a 24mm carb it would be illegal.

I did the test suggested, and yes, TeeZee's carb is legal ............

[TZ350]

The rules talk about carburation equiveilent to........ not, it must be a traditional slide carb...... and it has to be equivelent to the area of (didn't say, a traditional carb measured traditionaly) 24mm carb ............

Its not that they didn't think of it, I think they were leaving the door open to other carb ideas other than the traditional motorcycle slide carb, so that some could use a kart carb or automotive or make or modify something for themselves.

Tell me how can you specify a measuring method that covers all carb possibilitys, other than the light or turd method......

[TZ350]

It seems to me that if a manufacturer like Mikuni or Keihin sell you a (for instance) 24mm carb, you........

........... should not be allowed to mess with it or modify it in any way.

[TZ350]

I did the test suggested, and yes, TeeZee's carb is legal ............

You did Yow Lings test with my carb!!!!!!....Dad is not too pleased.

[Buckets4Me]

but it must be the eqvivalent to a 24mm motorcycle carb,
:violin:

F4 2 stroke engines over 104cc are restricted to carburation equivalent to a single 24mm
carburettor, F5 4 stroke engines over 53cc are restricted to carburation equivalent to a
single 20mm carburettor.

(didn't know 100cc 4strokes F% bikes where restricted to 20mm carbs)

I dont remember the word motorcycle in there
and what happens when some bright spark bring a fuelinjected 2 stroke along

I personaly think that if a carb has a 24mm hole in it then it's all good (shouldn't matter if the holes gets bigger or smaller over it's length)

otherwise they should let us use 28mm carbs so we can keep up with all these new fast cbr150's that could come along

back when you and mike pened the rules
wasent it 125 air cooled 4 strokes ? (what happened there)

EDIT 140cc and no mention of water or air cooling for 4 strokes

[Buckets4Me]

7.1.4 A protest may only be made by a competitor who has competed in a race or
competition from which the protest ensues, or that rider’s representative where the
rider making the protest is incapacitated by reason of injury.

7.1.5 The protest must be submitted to the Steward of the Meeting in writing and
accompanied by a fee of $35.00 and must make reference to the relevant rule
alleged to have been infringed.

7.1.14 Protests in respect of machine specifications, rider conduct, and conditions of competitions must be submitted to the Steward of the Meeting no later than 30 minutes after the completion of the race or event from which the protest ensues.

7.1.15 Where a protest against machine specifications, including fuel or noise testing, is not
upheld, the protest fee shall be treated as a deposit against any cost of dismantling
and reassembling the protested machine and where necessary a comparison
machine, and the obtaining of comparison parts and manufacturers parts catalogues.
7.1.16 Where a protest against machine specification is upheld, the protest fee may be
refunded, subject to the result of any subsequent appeal. The rider of the offending
machine will be required to meet all costs as outlined in above.
7.1.23 Costs relating to any technical tests required to prove or disprove a protest shall be
the responsibility of the unsuccessful party.
7.1.24 Any decision being the outcome from a protest at an event cannot be overturned or
negated except by the appeal process set out in the Rules.

might be time to go to taupo and have a ride ( good luck )

F4 2 stroke engines over 104cc are restricted to carburation equivalent to a single 24mm
carburettor, F5 4 stroke engines over 53cc are restricted to carburation equivalent to a
single 20mm carburettor.

[TZ350]

:violin:back when you and mike pened the rules
wasent it 125 air cooled 4 strokes ? (what happened there)

Good Point.............

[RMS eng]

Good Point.............

check the old rules, when the rule was set for a 125 air cooled 2 stroke to have a 24mm carb,not 28mm with a spacer?,the four stroke rule was set at 140 or 145cc,and you could have 2,3 4, cylinders and water cooling ect ,i think that part of the rule has been from the start

[Buckets4Me]

check the old rules, when the rule was set for a 125 air cooled 2 stroke to have a 24mm carb,not 28mm with a spacer?,the four stroke rule was set at 140 or 145cc,and you could have 2,3 4, cylinders and water cooling ect ,i think that part of the rule has been from the start


carburation equivalent is not a 24mm motobike carb so it dose beg to ask what they ment

you could have a 24mm hole and tip the petrol in from a bucket

[TZ350]

2003 is the oldest rule book I could find and it talks about "carburation equivalent", carburation not carburettor.

So it looks to me they were leaving it open for any kind of fuel/air control system including kart carbs, fuel injection, automotive or even home made or modified carbs.

"carburation equivalent" are the key words...........

[speedpro]

The whole debate is over where it's measured. If a larger carb is modified so it now has a piece that has a cross-sectional area equivalent to a 24mm circle then it complies with the rules as written. The 24mm restrictor has to be part of the carb to meet the rules. There is nothing in the rules that says where the measurement is made, unlike karts. The idea of where the measurement was to be made may have been there but was not written in the rules. Personally I don't see a need to update the rules, though check with me after Taupo on that. I look on what TZ has done as a cunning idea to get around a restriction.

[TZ350]

carburation equivalent is not a 24mm motobike carb

Agreed................ I think the rule was carefull to not exclude any kind of carb/fuelling option.

[speedpro]

2003 is the oldest rule book I could find and it talks about "carburation equivalent", carburation not carburettor.

So it looks to me they were leaving it open for any kind of fuel/air control system including kart carbs, fuel injection, automotive or even home made or modified carbs.

"carburation equivalent" are the key words...........

Selective quote there.

It actually says carburation equivalent "to a single 24mm carburetor". It's not talking about a fuel injection throttle body the equivalent size of a 24mm carburetor, it's talking about a carburetor system, say two very small carbs, that have a area equal to or smaller than a single 24mm carb.

I always thought of the wording as a way to stop guys running something like two 22mm carbs

[TZ350]

Selective quote here.

It actually says carburation equivalent "to a single 24mm carburetor".

Yes...... I stand corrected ........ :o on the quote thing.

[Yow Ling]

Selective quote there.

It actually says carburation equivalent "to a single 24mm carburetor". It's not talking about a fuel injection throttle body the equivalent size of a 24mm carburetor, it's talking about a carburetor system, say two very small carbs, that have a area equal to or smaller than a single 24mm carb.

I always thought of the wording as a way to stop guys running something like two 22mm carbs

So if you fitted a EFI system, there is no venturi necessary you could have a slide or butterfly how do you measure it as carburetion equivelent?do you allow for the butterfly shaft? it could get pretty messy
if you put a 24mm restrictor in the system as is pretty standard practice in most other motorsport the problem is solved and tzs system is legal.

[Buckets4Me]

Selective quote there.

It actually says carburation equivalent "to a single 24mm carburetor".
so realy you are only allowed a single 24mm carburetor then and nothing but a 24mm carburetor maby a 22mm carb bored out to 24mm. or a 28mm sleaved down to 24mm ?(with the sleave taperd so it flowes better


so why not just a 24mm carburetor and not the equivalant (and what is equivalant anyway?) what about fuel injection with a 24mm butterfly ? that would be deamed equivalant wouldn't it ? (new cbr125's)



shut up anyway Mr Green we are only trying to catch up to you :facepalm:

[Buckets4Me]

Selective quote there.

. It's not talking about a fuel injection throttle body the equivalent size of a 24mm carburetor,



I always read it as it was


why make it equivalant to a 24mm carb instead of say just a 24mm carb?

[Yow Ling]

I always read it as it was


why make it equivalant to a 24mm carb instead of say just a 24mm carb?

because the then awesome T125 stinger had 2 carbs that exceeded the 24 mm equivelent. (maybe true, only the bucket historians will know)

[Henk]

So that you could run two 17mm carbs if you felt so inclined? 452 mm2 split over both cylinders of a twin to give same area as a 24.

[Buckets4Me]

because the then awesome T125 stinger had 2 carbs that exceeded the 24 mm equivelent. (maybe true, only the bucket historians will know)

I guess that would make sense as if it had 2 carbs you would want to be able to run 2 carbs again but a single 24mm carb makes it hard

[speedpro]

It was written to stop smart asses using two 24mm carbs. There was buckets round with 2 carbs at the time. I know of one that had a carb on the rotary valve and one on a crankcase reed on the same engine. If we had just said "24mm carb restriction" then you have to use a 24mm carb, but as many as you like.
The rule was a bit unfortunate for the 125 twins but the one I've seen ran just fine with some copper plumbing fittings and a single 24mm carb.

[F5 Dave]

because the then awesome T125 stinger had 2 carbs that exceeded the 24 mm equivelent. (maybe true, only the bucket historians will know)
Well the Stinger was fitted with Amal carbs in some markets:sick:, but they are queer downdraught units. Must finish mine (roadbike).

[jasonu]

Its not that they didn't think of it, I think they were leaving the door open to other carb ideas other than the traditional motorcycle slide carb, so that some could use a kart carb or automotive or make or modify something for themselves.

Tell me how can you specify a measuring method that covers all carb possibilitys, other than the light or turd method......

That's easy, you measure it the SAME WAY as the manufacturer did.


you could have a 24mm hole and tip the petrol in from a bucket

Yes you could (hillbilly)


2003 is the oldest rule book I could find and it talks about "carburation equivalent", carburation not carburettor.

So it looks to me they were leaving it open for any kind of fuel/air control system including kart carbs, fuel injection, automotive or even home made or modified carbs.

"carburation equivalent" are the key words...........

You are correct


The whole debate is over where it's measured. If a larger carb is modified so it now has a piece that has a cross-sectional area equivalent to a 24mm circle then it complies with the rules as written. The 24mm restrictor has to be part of the carb to meet the rules. There is nothing in the rules that says where the measurement is made, unlike karts. The idea of where the measurement was to be made may have been there but was not written in the rules.

That is my entire point. The rule needs to specify WHERE the measurement should be taken and IMO it should be the same place as where the manufacturer takes the measurement it in the venturi where the slide is. As for FI the same goes, where the manufacturer measures it. If you have a home made carb, it will be up to you to prove its legality.


So that you could run two 17mm carbs if you felt so inclined? 452 mm2 split over both cylinders of a twin to give same area as a 24.

Yes you are correct.


It was written to stop smart asses using two 24mm carbs. There was buckets round with 2 carbs at the time. I know of one that had a carb on the rotary valve and one on a crankcase reed on the same engine. If we had just said "24mm carb restriction" then you have to use a 24mm carb, but as many as you like.
The rule was a bit unfortunate for the 125 twins but the one I've seen ran just fine with some copper plumbing fittings and a single 24mm carb.

Pete Steadmans Rat motor. Didn't work though. The front faceing carb hole was blocked off when I bought it.

[F5 Dave]

Yeah just hit quote as you did & submit, then do it again on the other post, & copy what you see & hit the back button & edit into your old post & paste it in. etc.

First bucket I was offered (I'm glad I didn't buy) was a YB100 with a scooter barrel on & disc & piston port carbs.

Not really much point in having multiple carbs (beyond trying to slip a loophole restriction). Even if you had short inlet timing & huge amounts of area with two carbs you could replicate the same with one huoge carb. The suction would be reduced by the same amount so would behave as a too large carb would. You'd still need to have the longer inlet duration to get more air in as the engine suction would be constant.


the only exception I can see is if you had a separate carb feeding the boostport, or possibly supplementing the transfers with a direct reed arrangement & only flowing when the pipe is sucking. Actually thinking about it, on a disc valve arrangement this might be worth while, as a reed engine will continue to flow the boost after the reeds have stopped filling the crankcase. So if you had a disc valve 100 with marginally restrictive carb size & a reed trapdoor into the boost port with a small carb feeding it without disrupting the main flow you could benefit. Sounds like a KE/RG100.

cheques to the usual address.

[rwh]

Yeah just hit quote as you did & submit, then do it again on the other post, & copy what you see & hit the back button & edit into your old post & paste it in. etc.

For quoting multiple posts? The Multi-Quote button (bottom right of each post) is what you want.

Just hit that on each post you want to quote, then hit reply to thread.

Richard

[Buckets4Me]

-------------------------


I'm not sure what you are trying to say but I'm reading ?
:facepalm:

[TZ350]

-------------------------

Some of us can read brail and my reply is Dr no, no ......... :nono:

[F5 Dave]

He has edited the other posts, you can delete them too.

Multiquote button! Hey I hadn't seen that:blink:

[Rick 52]

Thanks to the guys at ESE I have a better power curve now as well as 20 BHP ..This was by replacing the old standard TF Ignition with a CR 85 set up ..The fly wheel taper was wrong so I drilled the rivits out and bolted in the correct centre with correct taper ..
We increased the ex port timing by raising the ex port height by 1mm (more to go) and cutting 5mm of the rear of the piston skirt increased the inlet port timing ..After all the hard work I am looking forward to trying it out tomorrow but more looking forward to riding it at Tokoroa
as last year I couldn't enjoy the great track because the bike was so hard to ride with the small power band and overall lack of power !

[Rick 52]

Its miles better ! I didn't need to change down then back up through the infield and after going from a 230 to 240 then to a 250 main jet it felt even better..Even had a win for my troubles . Second race my throttle cable snapped of the start ,glad this was this weekend and not next ..
I made the cable and used Silphos to fit the nipple and I think this has made it brittle so will use soft solder next time..

[richban]

Its miles better ! I didn't need to change down then back up through the infield and after going from a 230 to 240 then to a 250 main jet it felt even better..Even had a win for my troubles . Second race my throttle cable snapped of the start ,glad this was this weekend and not next ..
I made the cable and used Silphos to fit the nipple and I think this has made it brittle so will use soft solder next time..



Will be interesting to see the comparison from the last time we raced. I was surprised how fast it used to exit the corners back then for the power it had. I will have my camera again. Lets try not to crash on tape this time. I was trying to find a really close call from the GP but I have lost a heap of footage. Gutted. Will be good to catch up again.

[Rick 52]

Looking forward to catching up ! Yes no crashing on film this time lol!
I have a spare cam for Wills xl ( xr) should I bring it for your bro to have a peek at ?

[richban]

Looking forward to catching up ! Yes no crashing on film this time lol!
I have a spare cam for Wills xl ( xr) should I bring it for your bro to have a peek at ?

Yeah good idea. Do you have a spare piston. The bigger the valve pockets the better the cam can will be. I had a quick look for a hi comp piston but didn't see anything.

[Rick 52]

Yeah good idea. Do you have a spare piston. The bigger the valve pockets the better the cam can will be. I had a quick look for a hi comp piston but didn't see anything.

Just a standard old piston ...But could order a new standard piston !

[richban]

Just a standard old piston ...But could order a new standard piston !



Ok. Bring standard old piston. Might be able to bodge some valve pockets into it. Would be good for a play.

[speedpro]

Just a standard old piston ...But could order a new standard piston !

Old piston and run the bandsaw through the middle. Then you can look and see how much metal there is in the pockets. The same treatment of an old head is good for shedding light on where to go with the grinder.

[Henk]

I can drag a seriously abused 1mm over version of the same piston along if it will help.