#6

[Sketchy_Racer]

any hint as to what it's making at the moment

More than 1 less than a million :laugh:

[speedpro]

19.2 at revs unknown. No graphs yet.

[speedpro]

Been busy taking 40mm out of the header pipe. Keen to get it on the dyno before the next meeting as I really would like to check this and the other wobbly pipe. With the slip joint it makes it heaps easier getting it on and off whilst fixing it so it fits properly. Turned out to be a whole lot more work than I thought to shorten the header as I had to redo the whole muffler direction and mounting as it interfered with suspension linkage once I'd cut a bit out. I'm pretty sure i can cut 20mm out of the centre section without having to redo the thing again. I'll make it with a slip joint so I can play with it without too much drama.

[speedpro]

quote Sonic-V "Any chance you could show the power curve even if against road speed? I am particularly interested to see if you actually have a double hump to your curve which would indicate some sort of recovery. "

This is exactly what I got on the dyno with the first Wobbly pipe as seen in the above post. It had what looked like a normal sort of peak but instead of falling off past that it fell a bit and then peaked again to about 75% of the main peak. Removing 40mm made it worse as well. I wasn't sure which engine Wobbly had designed the pipe for but I think now it was for the old style one which he was pretty scathing about. Pity I didn't build it in time to try on the old one as he reckoned 25hp at the rear wheel.
Anyway . . . . I tried the new laser cut pipe which I've made for the RS chassis with it hanging out the side on the dyno and it made an immediate nearly 2hp increase. The jetting was on the lean side of perfect I think and the timing was a bit advanced, things we had been trying to get the first pipe to work. Not only did the new pipe make more power but it had a good spread as well. We were in a gear which peaked at a bit over 100kmh on the dyno and the power was flat(ish) at peak for 30-40kmh, and the double hump disappeared. It ended up making 20.9hp with more to come I'd say.
The 2nd hump on the first pipe was at horrendous revs, way more than I've tried before. We tried another pipe John had hanging up but the motor didn't want to know. Another old-school pipe that resulted in a lot of crackling in the pipe at it's peak revs.

[TZ350]

.

Great Stuff Speedpro, the 2-strokers are moving ahead of the smelly 4-smokers in the power race.

.

[speedpro]

Pretty colours after four dyno runs

[jasonu]

quote Sonic-V "Any chance you could show the power curve even if against road speed? I am particularly interested to see if you actually have a double hump to your curve which would indicate some sort of recovery. "

This is exactly what I got on the dyno with the first Wobbly pipe as seen in the above post. It had what looked like a normal sort of peak but instead of falling off past that it fell a bit and then peaked again to about 75% of the main peak. Removing 40mm made it worse as well. I wasn't sure which engine Wobbly had designed the pipe for but I think now it was for the old style one which he was pretty scathing about. Pity I didn't build it in time to try on the old one as he reckoned 25hp at the rear wheel.
Anyway . . . . I tried the new laser cut pipe which I've made for the RS chassis with it hanging out the side on the dyno and it made an immediate nearly 2hp increase. The jetting was on the lean side of perfect I think and the timing was a bit advanced, things we had been trying to get the first pipe to work. Not only did the new pipe make more power but it had a good spread as well. We were in a gear which peaked at a bit over 100kmh on the dyno and the power was flat(ish) at peak for 30-40kmh, and the double hump disappeared. It ended up making 20.9hp with more to come I'd say.
The 2nd hump on the first pipe was at horrendous revs, way more than I've tried before. We tried another pipe John had hanging up but the motor didn't want to know. Another old-school pipe that resulted in a lot of crackling in the pipe at it's peak revs.

Hey Green, is that 20.9 John HP or actual 'corrected' HP? (John HP +10%ish from memory)

[speedpro]

Corrected I presume, the graph showed a smaller number and John had his calculator out before giving me an actual number.

[jasonu]

Corrected I presume, the graph showed a smaller number and John had his calculator out before giving me an actual number.

Nice going. DT said you are hauling my bike to Taupo for the GP.
Hope it doesn't blow a crank...
Good luck to you both and make sure you put it to the valve'n'camers.

[speedpro]

I'm expecting the crank to blow, it's what your bikes do at Taupo - blow cranks.

[Buckets4Me]

make sure you put it to the valve'n'camers.

I think there should be an easy 7-10 smokers that should be able to put it to the valve'n'alsorans easily (if the riders can is the next question)

[speedpro]

F5 should be able. Put him on a bike with twice the power of his 50, light fuse, stand well clear.
No pressure Dave, :first: or :bash: for you.

[speedpro]

Just found a real nice free viewer of ".dxf" files from solid works called Solid Works E drawings 2010. I have the dxf file for my laser cut pipe but the SolidWorks program i have wouldn't display it properly. This s/w does and converts it to a number of other useful file formats such as jpg.

[speedpro]

I'm using the depression "post-TRRS" to motivate me in getting this bike going properly.

My sister-in-law Viv sorted out the individual pipe pattern pieces onto separate A4 pages but I had a problem printing them where they were each scaled differently. Skunk thought he may be able to convert them to something I couldn't stuff up and he was right. I've cut the paper patterns out and now just have to translate it onto .8mm mild steel. It is still scaled ever so slightly down but it may better match the engine in the FZR which has a smaller exhaust port. Easy to compare on the dyno once built.

[Skunk]

I can print copies for anyone else for a mere $300 - that's right isn't it Speedpro?


Yeah right!

[speedpro]

Anyone who knows Skunk should go and say goodbye, soon.

[speedpro]

Bit of progress on the pipe front. One pic shows the steel with paper attached all sellotaped up so it fits the FZR and the other two are the pipe ready for spring mounts etc. Should be able to fire it up this weekend. If this all works I'll transplant the "other" cylinder and head into the bike and sort out a radiator. I'm really looking forward to see how it goes.

[F5 Dave]

Looks like quite a Big header & makes the first diffuse section look like it blends with the header. Strong taper on the header too? Also the stinger looks big, or is that just a larger transition for an internal stinger?

Ahh heck it's hard to judge these things from pictures, maybe I'm up the cock cause the first pic doesn't look that odd.

[speedpro]

From my scribblings when on holiday a while back, this pipe has design characteristics of a peaky pipe. The header is more steeply angled than otherwise which is how the peakier designs were in comparison. Compared to my designs which had a fixed diameter centre section and a less steep later part of the diffuser cone, this pipe has a steeper late part of the diffuser and a reasonably fat centre. I may build a few straightish versions to test on the dyno. Way too much work to make curved ones just for testing. There is a precise diameter and length nozzle at the exit of the baffle cone and the pipe you see slips over it and is a couple of mm bigger.

[F5 Dave]

yep figured you'd be on to it.

[speedpro]

Finally got it all together, springs everywhere, slip joint to cylinder, pin with R-clip to chassis and more springs for tailpipe to chamber over the nozzle. Got the 20mm one fitted at the moment. I've only been for a quick ride to the end of the road and back and already I can feel that it has more grunt but in a much reduced spread. Without trying, and unexpectedly, it picked the front up after I turned around to come back down the road. For the muffler bracket I was going to go the ESE way and use a piece of structural steel, maybe a small chunk of UB. In the end though I went with .8mm sheet pieces with a 3mm gap and the edges welded. It's turned out amazingly strong and once bolted to the small piece of 3mm panel I've brazed to the rear subframe you can't move it. Unfortunately i think it's going to be a scraper as the rear cone is back beside the suspension link meaning the pipe is out the side a little bit.

[TZ350]

Without trying, and unexpectedly, it picked the front up after I turned around

You skite……..:clap:

It looks good, I am looking forward to the dyno results and your on track impressions….

Team ESE might have to lift it's game.....

.

[TZ350]

A good look at Speedpro's number 6:- http://www.youtube.com/watch?v=J3Wsd9kx23Y

[SS90]

a KT100 piston?

Is a competition based engine part legal?

[Bert]

a KT100 piston?

Is a competition based engine part legal?

Yes in the case of pistons, ruling on this change about 5 years ago.

[SS90]

Wow, ok, missed that one....makes sense I guess.......

[Bert]

yes, one of the better rules changes in the last 15 years...
opens the door for cheaper options.... I use to dread ordering RG400 pistons; for my mobile piston eater.

[Buckets4Me]

JC made an mb100 specialy to finish off rs125 pistons (or so the story I heard goes)

[SS90]

JC made an mb100 specialy to finish off rs125 pistons (or so the story I heard goes)

Picture, or it never happend......

[TZ350]

Picture, or it never happend......

Garry in white leathers and leading on the JC MB100 racer modified to take RS pistons, Karl Morgan CB125T bored to 145 and 19 RWHP followed by Nigel Duff RG150 sleeved to 100/RSframe.........http://video.tiscali.it/canali/truveo/3605032337.html

[speedpro]

That's actually my video, cheeky b'stards, from my YouTube

[Buckets4Me]

Picture, or it never happend......

now that could lead you down the garden path

now about this super fast gn125 :)
lol dont worry about the pics it's a gn so it will look like the dogs lunch

[Kickaha]

now about this super fast gn125 :)
lol dont worry about the pics it's a gn so it will look like the dogs lunch

The Mighty GN is the pinnacle of four stroke bucket racing , the FXRs are just pretenders to the throne

Pic1, the mighty GN
196080
Pic2, Typical two stroke bucket
196079

[koba]

The Mighty GN is the pinnacle of four stroke bucket racing , the FXRs are just pretenders to the throne

Pic1, the mighty GN
196080
Pic2, Typical two stroke bucket
196079

Hey, that slut looks almost identical to my bucket!

[TZ350]

The Mighty GN is the pinnacle of four stroke bucket racing

the mighty GN
196080


I am having to think about a new frame, is that GN yours, it looks good, are those RG, RGV250 front forks and what sort of swing arm is that?

[Kickaha]

I am having to think about a new frame, is that GN yours, it looks good, are those RG, RGV250 front forks and what sort of swing arm is that?

Yes it is, at one stage one of the fastest bikes down here in the pre FXR era and quicker than the SS90 GN (wouldn't be to hard as he rides like an old lady)
won the 2001 championship (before I owned it) and second the two years (02-03) after that with me riding it to the filthy two stroke ridden by Diesel pig who said he could only beat the GN because of the extra HP he had

GSXR250 front end
GSXR250 swingarm (took a lot of modifying to make it fit)

[SS90]

Yes it is, at one stage one of the fastest bikes down here in the pre FXR era

GSXR250 front end
GSXR250 swingarm (took a lot of modifying to make it fit)

Two words spring to mind..... TART's, and HANDBAG

[Buckets4Me]

Two words spring to mind..... TART's, and HANDBAG

actualy I think it looks a lot better than I thought
I was thinking it would look more like the 2 smoker you had there :p


second the two years (02-03) after that with me riding it to the filthy two stroke ridden by Diesel pig who said he could only beat the GN because of the extra HP he had

was sort of the reason we went 2 stroke

[speedpro]

Finally got up to John's and spent a few hours filling his workshop with 2-stroke smoke. The end result with the new pipe was a very similar power curve to the final run from the previous dyno session where I had the laser cut Wobbly pipe hanging out the side of the bike. We got another 1/2hp out of it with a bit of fiddling and it looks like a bit more there with a smaller main jet. We can also lift the curve across the top by fiddling with air correction jets, maybe.
One of the things we tried was the different size nozzles on the pipe. I had been running a 20mm nozzle and tried the 19mm nozzle at the track last time. It felt better and I liked it. I wasn't expecting anything in particular so that was a pretty honest feeling that it was better. Well, on the dyno the 19mm nozzle only had one effect and that was to knock the power on the head, just a little bit. The 20mm nozzle worked better. We will revisit that a bit later.
We've set the timing a bit advanced from best peak power as it gives a good lift as the motor comes up on power with a pretty useful 1/2-1hp everywhere except peak. Pretty obvious I need one of those programmable CDIs.
On the carb side it 4-strokes at any small throttle settings at nearly any revs. Give it a bit of throttle and it cleans up immediately. Next time at the track I'll drop the needle a notch. I may have to have a look at the carb slide but I'm not too worried as it carburates well as it is when used as intended. I was able to go to full throttle on the dyno at not much more than a fast idle.
Dyno runs were done in 4th gear with a top speed of about 100kmh. The curve builds nicely and then flattens off for a good 30kmh. Over that range it's a straight line and nearly flat.

The peak we got was 21.4hp so still more to go to match old #6 but not too bad. I'm also going to play with the reed free length as this motor revs on & on and the reeds may be a bit long for the revs, resonance and all that.

[jasonu]

What is this 'nozzle' you referring to? Stinger maybe?
Nice HP, any chance of seeing a run sheet? From memory JC's dyno didn't offer that but a smart guy such as yourself could use the data to hand draw a graph.

[speedpro]

Been fiddling a bit more. This time I just want to test the new 34mm carb on something I'm familiar with. I've got a whole carb/cable/throttle setup for each carb so real quick and easy to swap. The power jet feed tube snapped when I was trying to refit it so I have to fit another tube. Other than that I've glued a choke button from another Mikuni carb into it, tipped some fuel into it and gave it a push. I'd gone about 4 steps and it was running at a fast idle. Throttle response seems as good as the old 32mm but we'll see this weekend. If this all works fine the next step is fitting the other barrel and head with radiator.

[speedpro]

Bit more playing round has seen a dummy assembly of the good motor. The radiator is just hanging on a bit of alloy wire at the moment but the mounting lugs for the original radiator are in exactly the right place. Mitre10 don't know it but they have a really good stock of bucket racer watercooling copper pipes of various angles. I love this big chassis, plenty of room to just fit things in. I'm gonna give the RG50 radiator a go, it'll be obvious enough if it isn't up for the job.

[aircooled]

i think the motor is way too big for that chassis!, head looks great, did you weld it up yourself?

[TZ350]

.

Team ESE are watching the development of this engine with interest..............:shifty:

Many thanks for your help with our own FZR projects............

[speedpro]

i think the motor is way too big for that chassis!, head looks great, did you weld it up yourself?

I cut and turned up all the bits and dropped it off at Darren's workshop for welding. When I picked it up someone had replaced the circumference bit with a piece of treadplate. They're a bunch of comedians.

[TZ350]

I cut and turned up all the bits and dropped it off at Darren's workshop for welding. When I picked it up someone had replaced the circumference bit with a piece of treadplate. They're a bunch of comedians.

Yep............They're a bunch of comedians..........I wounder why it had treadplate on it..................:laugh:

[F5 Dave]

Yeah treadplate & spring washers. It's a bucket, I love it!

Looks room in the first pic to put your legs either side of the engine for some Fred Flintstone Power Assist.

[speedpro]

Couldn't help myself today. Have got the "good" engine all together now but the radiator is just hanging there. After working most of the day round the house I just had to start it. Same old 4 paces and it was running. I've fitted the 32mm roundslide Mikuni for the time being to reduce variables and it sounds crisp. One little leak of water from the head so there'll be a warranty claim going in to Morgan's this week.
Got a small collection of cardboard boxes now. Had to juggle base gasket thickness to get the squish clearance right.
The thermosyphon thing seems to be working. It warmed up the top of the radiator, but we'll see once I start riding it properly. Need to sort out a temp gauge yet.

[F5 Dave]

Ahh Devcon will plug it. Temp gauges. Hmm. Great idea, Darrin ran one for years, but I've been through several & all have stopped working for some reason or other.

[speedpro]

All together and doesn't seem to be leaking. Warmed it up with a piece of clear plastic tube on the radiator cap overflow pipe and it pushed about 50mm up. With the bracket extending back to the frameand solidly mounted I think it's killed a lot of the vibration it had so it had the effect i thought it would.215056215055215054215053

[bucketracer]

Interesting looking setup for the radiator, thinking of a water cooled 100 ourselves, just for shits and giggles mind....:yes:

[speedpro]

Did a few laps at Mt Wgtn today, between rain storms.
New piston in freshly bored cylinder with the full-on port job, water-cooled head, short stroke crank and big reed valve plus all the rest. Took it very easy for a start. My nice temp gauge doesn't work when the engine is running. Pretty sure it doesn't like the ignition. Felt OK off-pipe, reasonably driveable, but a bit flat further up. Followed by the oh-my-god hit as it all came to life. This engine is a screamer. The couple of times I gave it the revs into the back straight it just revved on and on. The old motor had to be shifted up just before the left into the infield but not this one and I could use that lower gear right round to the hairpin. At a guess I'd say it pulling something like 14,000rpm with no sign of fading out. I only ran the old 32mm round slide Mikuni as the 34mm carb needs a bit of sorting. This'll probably come back to haunt me but it seems to make a bit of power, maybe it's just the transition from off-on power though. Pulling into the pits and killing the motor brought the temp gauge back to life. It read "HI" meaning it was over it's 70deg C max but immediately dropped to 69.9 so I figure it's running at about 70+ deg, just a tad high. Will check all that out on the dyno some time.

[speedpro]

Being the cautious type, I pulled the motor apart to have a quick check. I found the cylinder had a few very shiny patches and a few areas that almost looked like the piston was maybe just starting to pick up.
I took it to the local very friendly kart shop (Alpha karts) to get someone who is familiar with cylinders running KT100 pistons and which had been finished with a cork hone to have a look. As I said, very friendly kart shop, they fitted a new ring into the cylinder and we had a good look at it with a light behind. I'm pretty pissed off as there was a definite section where light could be seen between the ring and the bore. The cylinder is not round. The shiny patches are how it is supposed to be. With a cork hone finish the cylinder ends up with a very fine honing pattern. Once run it ends up being a mirror finish. Kart shop guy was heading out so he took the cylinder to his engine guru. Still awaiting feedback but it should be fixable. I'm just a bit worried about the tiny bits where it looked to be picking up.

[speedpro]

I'm going to stick with the standard Yamaha KT piston and ring till everything is sorted. Once I'm happy I might swap to these new rings that the guy showed me. They have a tiny titanium face and have less tension on the bore = less friction, but because of the material they are made of they don't flex and still seal. Have to use the right piston as well but they are supposed to be worth useful horsepower.

[speedpro]

Got it all back, straight, round, and not tapered. Alpha kart's engine guy has honed it with a more normal 240ish grit hone and it's now out to 52.2mm(ish) bore with a 52.15 piston. I got a 52.15 ring (stupid) but the gap is too big in the 52.2 bore. A minute with the calculator says the gap will be fine with the 52.2 ring the kart shop guys suggested (smart) or maybe even a 52.25 ring.
These KT pistons and rings are great. So many sizes and the prices are great compared to regular bike stuff, plus you can walk into any kart shop and buy off the shelf any size you want. Piston and ring is $118.
I'm going to run in the engine a bit harder this time as well as there was a thought that it may not have been worked hard enough at the start.
The other change which is a biggy for me is I'm changing oil. Currently on Motul 800 which is a great oil and has given me no problems at 40:1 in various motors. I'm going to give Elf 909 HTX a go. It looks like it may be beneficial in a really high revving engine. The high revving kart engines like it but at 20:1 you have to wonder.
I asked nicely and the wife will be picking up the ring tomorrow. One of the few shops I won't have to worry about her grabbing a few extra things.

[F5 Dave]

Misunderstood the instruction & she heads past the jeweler & scores that eternity ring that she claims she's been waiting an eternity for. :facepalm::facepalm: (that's a double).

[Buckets4Me]

Misunderstood the instruction & she heads past the jeweler & scores that eternity ring that she claims she's been waiting an eternity for. :facepalm::facepalm: (that's a double).

snap i was going to ask if Michel Hill had kart rings :)

well shell get the next best thing for ya
and some matching earings

[speedpro]

got all the bits and dummied it up. The squish clearance was a bit tight so measured the paper gasket and decided what size base gasket was needed to get the clearance right. Darren (Morgan Engineering) gave me a bit of stainess sheet the right size which I roughed out using his gear. Spent a bit of time getting it right and assembled it all again to find I'd just wasted a few hours as the clearance was now .1-.2mm on the high side. Darren had also given me a sheet of .1mm aluminium so I cut 3 more base gaskets from that and added one to the paper gasket and reassembled it again. Now it is spot on. Whilst messing round also made sure that the head was pulling down tight in the barrel. I had a thought that it might not be as the o-ring is a real tight fit. Measurement of the squish, with and without the o-ring, shows no differences so I suppose it's all good. Should have it all together properly tomorrow. The head isn't located as accurately as I'd like on the cylinder. It can move about a bit before tightening with the result that the squish can be a bit tight on one side and a bit loose on the other. Only +-.1mm or so but . . .
Looking forward to getting it out on the track.
Scored another bucket as well, lets call it #3. Just got to sort the new rear sprocket. My boy seems sort of keen so I need to arrange some gear for him, and Darren's daughter may be having a ride as well. Got the bits I needed to sort it from Total Motorcycles including a decent size sheet of fibreglass for reed valves if someone needs some made.

[speedpro]

Fired it up last night and if anything it seems even crisper than before. Only problem is I can only find one spark plug which is the fouled one from the MB5 so it won't pull a load without problems. Looks like I'm going to be forced to buy a new plug after I don't know how many years. My eyes are good after a couple of operations as well so I'm really looking forward to this weekend.

Does anyone have a sprocket for a MB5 I can borrow this weekend, please?

[speedpro]

Took it to the track today. Ran it in fairly hard for me. With the B8 plug and not thrashing it came out near perfect. Put a B9 in and thrashed for a session and that looks fine also. Checked it out and it is all looking good. Couple of streaks above the ports but running a finger over it you can't feel anything. The photos are as it was when I took the top off. Clean as a whistle with a sheen of oil. The o-ring looks "worn" but actually is fine.
I don't think it's actually making much power. It revs good, but not much power.

[Rick 52]

Looks good ..

[TZ350]

Checked it out and it is all looking good............
I don't think it's actually making much power. It revs good, but not much power.

It does look good............"not making much power".........I hear its a rocket ship...:yes:

[speedpro]

Damn, that confirms what I was thinking, I'm slow:facepalm:

[speedpro]

As that Gary bloke said in his song years ago -
"It's good to be back"

The motor is a screamer. It definitely needs to be in the right gear and even in the straight if I changed a bit soon I had to wait for it to pick up. Doing it all right though it makes good progress. Just need to get it on the dyno and optimise the tuning plus I want to try the 34mm carb before Taupo. An ignitech ignition will be a useful addition I think to pick the power up off peak.

[F5 Dave]

would you look at the size of that exhaust port!:shit:

[jasonu]

As that Gary bloke said in his song years ago -
"It's good to be back"

The motor is a screamer. It definitely needs to be in the right gear and even in the straight if I changed a bit soon I had to wait for it to pick up.

In other words peaky. Sorry Mike.

[F5 Dave]

Don't worry I'll teach how to abuse those poor clutch plates.:innocent:

[speedpro]

progress . . big radiator and temp sender. Uses standard FZR filler cap bit

[F5 Dave]

aww man! take the sharp edges off that plate of ally before H&S clamp down on yer ass,.

[speedpro]

Well , it doesn't make 29.2hp. The clutch slips so it's hard to tell. Every run it would let go as it really picked up. I tried a run at less than full throttle and it revved on nicely making average horsepower. Surprisingly it liked more advance. Every time the timing was advanced it made more power and better. Rob ended up sawing a bigger notch in the crankcases for the pickup which pokes through so we could turn it far enough. It may like more yet but we called it quits as the clutch was letting go and may have been getting worse. Still running the old 32mm round slide Mikuni and never got to the jets so hopefully more power with jetting and should be for sure with the 34mm flatslide. From first to last run we gained about 5hp so quite nice for just timing changes.

[Rick 52]

So what will you do with the clutch ? will it have to have a new type basket or better springs and plates ...Sounds great..

[speedpro]

This clutch is already well modified. I've machined the steel plates and the alloy bits that clamp them so an extra pair can be fitted. Like that and with stock springs and no spacers it's been good for years with no problems. I still have the spring spacers so I'll put them back in. With the stock clutch pack but with the spring spacers it handled the old 22.5hp but made the lever hard and the clutch was not as nice to use. The combination of extra plates and spring spacers should be OK. Failing that I'm going to have to cheat.:shifty:

[Buckets4Me]

This clutch is already well modified. I've machined the steel plates and the alloy bits that clamp them so an extra pair can be fitted. Like that and with stock springs and no spacers it's been good for years with no problems. I still have the spring spacers so I'll put them back in. With the stock clutch pack but with the spring spacers it handled the old 22.5hp but made the lever hard and the clutch was not as nice to use. The combination of extra plates and spring spacers should be OK. Failing that I'm going to have to cheat.:shifty:

I would go get some new plates after friday nights effort

[speedpro]

Since the last post we've had another session on the dyno. The motor is a whole lot better but doesn't make any more power. It has some monster main jet in it now - 1.85mm or something over 400. The power peak has been moving lower in the revs as the jet size has gone up so with a bit of fiddling with the air correction jet it should be possible to broaden the peak nicely. We ran out of gas on the dyno but just before that it seemed that the motor started running on and that caused a bit of worry. I took the pipe off to check what I could of the bore and the visible face of the piston. It all looked good so I tipped some old fuel into it and gave it a quick run up the street to make sure it is OK. I love it. This thing has a real 2-stroke hit and goes like stink. I only ran through a couple of gears but that was enough for a real big grin. I just love the sound of a 2 stroke on the pipe. I'm just hoping 30hp can be stretched out of it. It's just that magic number, the next big step. It'll be bloody frustrating if we can't get there.
I've bid on a generator and pickup on e-bay and once that arrives and we have the charging circuit sorted it'll be time for the Ignitech ignition.

[Sketchy_Racer]

haha,

Just ran my watercooled head for the first time last weekend, had the same sized radiator you had on before (RG50) and yeah also need to go larger doh!

I think a zzr250 radiator should do it and it's as light as the RG50 one, just holds a bit more water.

Unfortunately I will be happy if I make it into the 20hp bracket let alone 30hp you bastard!

[jasonu]

haha,

Just ran my watercooled head for the first time last weekend, had the same sized radiator you had on before (RG50) and yeah also need to go larger doh!

I think a zzr250 radiator should do it and it's as light as the RG50 one, just holds a bit more water.

Unfortunately I will be happy if I make it into the 20hp bracket let alone 30hp you bastard!

A water cooled head is better than no water cooling at all. But without watercooling the cylinder as well as the head, with a pump not thermosyphon, you have only done less than half the job. Especially if you are makeing heaps of power, you will need all the cooling you can get.

[speedpro]

Has anyone else heard from our European correspondant lately??

I'm actually confident that the thermosyphon cooling system on my MB will work fine. I would prefer larger diameter inlet and outlet on the head but apart from that it seems to work fine. My old AC50 was so well cooled I had to cover 90% of the RG50 size radiator. OK, the AC50 wasn't making as much power as the new bikes but it was only slower than Pete Sales GT50 in the end and he held the NZ land speed record, maybe still does. It's such a simple cooling circuit it really doesn't need a pump I think.

[koba]

he held the NZ land speed record, maybe still does.
Yep, He does.

[Buckets4Me]

I'm actually confident that the thermosyphon cooling system on my MB will work fine.

the beast was running cool on the dyno

top of the radiator was 60-70 deg and the bottom around 40 deg

head was around 40-45 deg and the cylinder was up to 70 deg sometimes

[bucketracer]

Has anyone else heard from our European correspondant lately?


I am not trying to be a "know all", but I have ALOT of experience with this subject matter..........

Man, you guys are way behind.... Oh, the 28 P.S is with my own exhaust as well........

Try not to hit the key board when you aim for the screen.................. aye guys!!!!!!!!!!!!!!!!

Maybe when he read you are knocking on the door of 30 P.S, he broke his computer screen when he hit it with the keyboard.......



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[RMS eng]

the beast was running cool on the dyno

top of the radiator was 60-70 deg and the bottom around 40 deg

head was around 40-45 deg and the cylinder was up to 70 deg sometimes

any 100cc two stroke making more than 22HP will lose power if it is air cooled,a while back i spent two days at Mt wellington helping some one with a TS100 motor i built for them,with water cooled head and no pump, after 10 laps head would 70-75 deg but cylinder would be 100-110 deg,but with head and cylinder water cooled and a pump motor would run at 65-70 deg,late 70s air cooled MX bikes could lose up to 20% in power after 15mins running from getting to hot.
chris p

[speedpro]

The old totally air cooled motor definitely lost it's edge after a couple of laps.

Last time at the track with the new motor, watercooled head, I couldn't feel any difference after any number of laps, and that was with the RG50 radiator. It was only peaking at about 25hp but even so. The temp was about 70 as it read "Hi" when I stopped the motor but immediately dropped to 70, 69.9, 69.8 and so on.

I do agree that ideally the head and cylinder both need to be watercooled but just doing the head supposedly gives you 80% of the benefits of water cooling. The requirement for a pump I disagree with for a motor that has the cylinder sloped forward. The water circulates at a reasonable rate once warmed up as witnessed with clear hoses and a bit of dirt in the water.

[jasonu]

The old totally air cooled motor definitely lost it's edge after a couple of laps.

Last time at the track with the new motor, watercooled head, I couldn't feel any difference after any number of laps, and that was with the RG50 radiator. It was only peaking at about 25hp but even so. The temp was about 70 as it read "Hi" when I stopped the motor but immediately dropped to 70, 69.9, 69.8 and so on.

I do agree that ideally the head and cylinder both need to be watercooled but just doing the head supposedly gives you 80% of the benefits of water cooling. The requirement for a pump I disagree with for a motor that has the cylinder sloped forward. The water circulates at a reasonable rate once warmed up as witnessed with clear hoses and a bit of dirt in the water.

You use dirty water???

[Buckets4Me]

You use dirty water???

only after missing a corner or 2

[F5 Dave]

He's using creek water 'cause that's the coldest.:blink:

[jasonu]

He's using creek water 'cause that's the coldest.:blink:

I used to piss in mine...

[speedpro]

I used to piss all "over" yours

[jasonu]

I used to piss all "over" yours

only when mine blew up...

[Buckets4Me]

only when mine blew up...

or you were not around

[bucketracer]

Is someone is taking the Piss......... :blink:

[speedpro]

I'm pretty sure Nigel used heavy water in his. Could be why it keeps melting down, Chernobyl and all that.

[speedpro]

Well, was at ESE at 6am today. We finished off adjustments, jets timing and air correction. The end result was 29.5hp(DIN). The graph shows the first and last runs and the increase we got. There's one more test with a slight mod to the pipe which I've seen make a nice increase but apart from that 30hp isn't going to happen with this engine I don't think.

Thanks to ESE for letting me fill their workshop up with 2-stroke smoke and especially to Rob for being so keen and helping do the tuning.225246

[speedpro]

Done a couple of meetings and a few laps of Taupo. Figured I should have a look inside just to check. It looks sweet with either fine crosshatch marks or a nicely polished surface. The piston has been used and has just the faintest marks on either side at the back. The photos are after Avalon had done a few quieter laps at Mt Welly. Interesting how the chamber is cleaned off a bit where the boost port is aimed.234107234108

[TZ350]

To my untrained eye, that looks a very good even patten on the piston.

With the boost port striking so close to the edge of the combustion chamber, does that mean its upward angle is set to high or is that where its supposed to be?

Hopefully Wobbly will describe what he sees in the pattens.

[jasonu]

To my untrained eye, that looks a very good even patten on the piston.

With the boost port striking so close to the edge of the combustion chamber, does that mean its upward angle is set to high or is that where its supposed to be?

Hopefully Wobbly will describe what he sees in the pattens.

After a full race meeting on my 1991 RS125 the pattern on the top of the piston looked like a map of Australia. The deposit was a lighter color than that in your pix. Might be due to the fuel I was using which was Av+castrol A747

[speedpro]

I've made changes to the riding position. Avalon commented it was like riding a couch with the seat and handlebar positioning. Because of that I've put the original FZR seat back on the bike rather than just sitting on the fibreglass tailpiece and placed the handlebars under the top triple clamp in the original position. Basically it's back to a stock FZR250 riding position. After riding the scooter all week it has a definite head down arse up feel to it. It was OK at the track today and I'm gonna give it a go tomorrow but my thoughts are that the handlebars are going back on top of the triple clamp. For some strange reason I was uncomfortable in the right onto the back straight, running clockwise, and tended to run wide. It also feels like I'd have less chance of saving it if something happened. My right wrist was letting me know about it as well as it's still unhappy after a big crash 30 odd years ago. It "looks" right so I'm thinking it's just me. My son has also commented that I sit upright more than others. could be that I know something others haven't figured out yet though that'd be a first.

[koba]

There is something odd with this thread, It tels me that speedpro made a post but I can't see it. Hopefully if I post here my post will become the most recent and it will stop telling me there is a new post that I can't read.

EDIT: and now I can see the last page, weird huh!

[F5 Dave]

Not really it was a stealth post.

I've noticed that my riding position on my 50 is quite uncomfortable whilst sitting on the dummy grid as I waited yesterday. Yet when riding the bike it is the best seat in the house. I like to be down low when cornering.

[jasonu]

Not really it was a stealth post.

I've noticed that my riding position on my 50 is quite uncomfortable whilst sitting on the dummy grid as I waited yesterday. Yet when riding the bike it is the best seat in the house. I like to be down low when cornering.

Complete opposite to Gossamers 'sit up and beg' position. I used to like the 'crouch' but I was younger (thinner) then...
Maybe a Harley or Goldwing framed bucket is in order???

[koba]

Not really it was a stealth post.

I've noticed that my riding position on my 50 is quite uncomfortable whilst sitting on the dummy grid as I waited yesterday. Yet when riding the bike it is the best seat in the house. I like to be down low when cornering.

More than one person I have spoken to about riding position has bought up your 50 as an example of getting it right. Thats without your 50 being the primary subject of the conversation too.

[speedpro]

The plans for bucket domination using a fleet of MB powered buckets is coming along. Currently in the garage are #6, an MB5, RS50 with H100 engine, MB100 engine lightly modified but getting worked on, MB100 engine over the top modifications, super modified MB100 for RS chassis, spare MB engine. There is a H100 away getting a water jacket on the head and barrell. All engines have 6 speed transmissions and I have fully modified clutch packs spare as well if needed. On the way are various good bits like an Ignitech ignition and generator system.

238718238717238721238720238719238716

[koba]

The plans for bucket domination using a fleet of MB powered buckets is coming along. Currently in the garage are #6, an MB5, RS50 with H100 engine, MB100 engine lightly modified but getting worked on, MB100 engine over the top modifications, super modified MB100 for RS chassis, spare MB engine. There is a H100 away getting a water jacket on the head and barrell. All engines have 6 speed transmissions and I have fully modified clutch packs spare as well if needed. On the way are various good bits like an Ignitech ignition and generator system.

238718238717238721238720238719238716

You have the sickness too...

Got any spare 6-speeds?

[koba]

The plans for bucket domination using a fleet of MB powered buckets is coming along. Currently in the garage are #6, an MB5, RS50 with H100 engine, MB100 engine lightly modified but getting worked on, MB100 engine over the top modifications, super modified MB100 for RS chassis, spare MB engine. There is a H100 away getting a water jacket on the head and barrell. All engines have 6 speed transmissions and I have fully modified clutch packs spare as well if needed. On the way are various good bits like an Ignitech ignition and generator system.

238718238717238721238720238719238716

Love the Curtains.

You have the sickness too...

Double (ish) post due to intoxication and a silly fuggin mouse with a back button on it.

[speedpro]

You have the sickness too...

Got any spare 6-speeds?

I'm gonna build up a spare bottom end so not really. The only other 6-speed has a few scorched cogs so only good for spares.

If anyone is interested I can make up more modified clutch packs. At the moment I can do a same day exchange. My packs fit an extra pair of plates in but are the same assembled thickness and operate exactly like a standard clutch. There is no need to use spacers in with the clutch springs. They're good for about 25-27hp at the usual rpm. Not sure what torque they are good for.

[speedpro]

Thanks to Rob and the ESE guys I've managed to get a few runs on the RS50 with the H100 engine. This motor has untouched transfer ports, an only slightly enlarged piston port, a "bit" bigger and higher exhaust port. We tried a nearly fully worked RD350 reed valve and a stock RD350 reed valve. We tried my old 32mm Mikuni and a downdraught 28mm Mikuni. The squish clearance is bigger than desireable at .9mm but the combustion chamber is nicely shaped. It has my old ignition fitted.
With the 32mm carb and the flash carbon reed valve we adjusted the ignition and put a 260 main in the carb. That gave us a reasonable 19hp. Swapped to the 28mm carb. Initially it was way worse but a few main jets later it was more or less equalling the 32mm carb. Strangely it produced less midrange by about .5-1hp. We then swapped over to the unmodified RD350 reed valve with the steel petals. There was an obvious difference as soon as it was started with a different sound. The runs sounded way different, rougher. It made a lot less power everywhere. The modified reed block looks to have a lot less area than the stock one but it must flow better.
End result is a reasonable 19.?hp at about 11,000rpm so OK considering the tune.

[F5 Dave]

. . . Swapped to the 28mm carb. Initially it was way worse but a few main jets later it was more or less equalling the 32mm carb. Strangely it produced less midrange by about .5-1hp. . .

Yeah it's queer how that can happen. I've had a mismatched inlet with a step for a smaller carb & it has run better with the bigger carb all the way through the range. Not textbook stuff esp when you are looking for a kart track midrange carb to swap over to.

[Ivan]

I reckon I have a Troy Bayliss rding style its in between sitting right up and hanging down low due to my height,

The RS frames are such a nice riding position

[koba]

Thanks to Rob and the ESE guys I've managed to get a few runs on the RS50 with the H100 engine. This motor has untouched transfer ports, an only slightly enlarged piston port, a "bit" bigger and higher exhaust port. We tried a nearly fully worked RD350 reed valve and a stock RD350 reed valve. We tried my old 32mm Mikuni and a downdraught 28mm Mikuni. The squish clearance is bigger than desireable at .9mm but the combustion chamber is nicely shaped. It has my old ignition fitted.
With the 32mm carb and the flash carbon reed valve we adjusted the ignition and put a 260 main in the carb. That gave us a reasonable 19hp. Swapped to the 28mm carb. Initially it was way worse but a few main jets later it was more or less equalling the 32mm carb. Strangely it produced less midrange by about .5-1hp. We then swapped over to the unmodified RD350 reed valve with the steel petals. There was an obvious difference as soon as it was started with a different sound. The runs sounded way different, rougher. It made a lot less power everywhere. The modified reed block looks to have a lot less area than the stock one but it must flow better.
End result is a reasonable 19.?hp at about 11,000rpm so OK considering the tune.

What sort of pipe did it have? (I know I'm on the pipe buzz at the moment, not not that kind of pipe buzz...)

[speedpro]

It seems to be a copy of the pipe Wobbly designed for my "good" motor. Not too surprising considering everybody worked at BSL at some time. Which means it isn't even close to the right design for where this is motor is currently.

[koba]

It seems to be a copy of the pipe Wobbly designed for my "good" motor. Not too surprising considering everybody worked at BSL at some time. Which means it isn't even close to the right design for where this is motor is currently.

True. From a quick run down the road I'm liking the feel of the RG400 (or 500, I'm not sure) pipe I've just grafted on to my MB which is probably around the same state of tune now. (Although with MB porting rather than H).
All ports on mine are standard except a bit of work on the inlet, head is standard with too much clearance in the squish band but I'm very happy with it at this point.

[speedpro]

Box of flash bits arrived today. The CRF250 rotor is a perfect fit on an MB100 crank. I got the whole rotor/stator/reg rec and capacitor. Very nice gear. Need the power for the Ignitech and the powerjet solenoid on the new 36mm carb.

[speedpro]

The carb isn't downdraught but is trick in every other way. You can see in one photo how the rotor fits the taper on the crank perfectly. The reg/rec is a tiny little unit compared to previous units I've played with. The generator is a single phase output but with 8 poles should generate enough power. It'll need to power a water pump as well on the next engine. I'm gonna try using the capacitor as per the original system but will go with a small gel cell if there's a problem.

239908239909239910239911239912239913

[speedpro]

and the stator239916

[Bert]

Hi SpeedPro.

36mm Carb; are you going to do anything to it or actually keep it that size?
I've got its brother sitting in my shed but I though it would be far to big for 100cc even in the state of tune of yours...
I might have to re-think the 28mm now

[F5 Dave]

Its pushing it, but RS125s come std with 39s & they sometimes run 41s.

28? pah! my 50 runs a 28. :baby:

Actually that isn't a bad size to be starting with

[speedpro]

28mm is fine for at least low 20s.

The 36 is being tried on the suggestion of the Wobbly one. The 34mm carb is amazingly good. The old 32mm round slide I always thought was a nice carb but the 34mm is better everywhere.

The 36mm carb has a solenoid controlling the powerjet which is the main feature I was after. The TPS may help make it a nicer bike to ride but funnily enough it's pretty nice now. The thing is you're either full throttle or hard on the brakes so the TPS shouldn't be such a great advantage, apart from helping to determine when to stop the powerjet.

[Bert]

...

The 36mm carb has a solenoid controlling the powerjet which is the main feature I was after. The TPS may help make it a nicer bike to ride but funnily enough it's pretty nice now. The thing is you're either full throttle or hard on the brakes so the TPS shouldn't be such a great advantage, apart from helping to determine when to stop the powerjet.

Thanks SpeedPro.
Well that’s something to seriously think about. I’ve got the Kx version but the powerjet is set rather low in the slide position (straight, where yours is pointing upwards).

Here I was pondering if I should close up a part of my 6 petal reed block and reduce the volume of the intake (and a smaller carb ~28mm). Now, not so sure.
I guess I’ll have to wait and see the results that you come up with....

I see your point about the TPS (that was the original point of getting the Kx carb: to expand the ignitech setting options).

Have you thought about a high temp thermocouple (with relay output) in the exhaust/or head to act as a retardant trigger??

Dimensions of the MB100 shaft / CRF rotor ? please; I’m having a shit of a time finding something to fit my project.

[richban]

I might have to re-think the 28mm now


Some number from the flow bench. Might help.

My new head will flow 125cfm. (32.5hp)

28mm Mikuni 110 cfm, (27.5hp max potential)

Carb in the bin. Next.

[speedpro]

The entry to my reed block matches the carb mounting flange and as smoothly as I could (be bothered) flows out to the ends of the reed cage. It almost looks like it would restrict the flow as the view of the reed petals is obscured but I've tried to keep the cross-sectional area uniform until it gets to the petals. With the splitter in the middle it definitely has a restrictive look to it.
The power jet is tapered on the back face, it doesn't open on the end. The position would seem to indicate that it flows at lower throttle settings.
I don't know about the shaft or taper sizes but the rotor is about 75mm OD. After getting the rotor and stator I would reccommend them, though I probably should wait till it's all running. The rotor is reasonably light though I haven't weighed it yet, so the engine should be real responsive now. More than standard as I'm not running the balance shaft.

[speedpro]

I'm running a 6 petal reed block with only one petal each side. I don't think it needed such a big reed block until the software said the engine was going to make some serious horsepower. The thing is that if the engine is going to be revved hard then the free length of the petals needs to be reduced to increase their resonant frequency. This results in shortened reed ports once the reeds open reducing the cross-sectional area. To keep the area you need to go wide, by possibly going to 6 petals. I think something like a Yamaha RD 4 petal reed block with the centre bridge taken out of each side gives you enough area for your average bucket engine. Certainly enough for low-mid 20s hp. You need to sort out the piston port on the MB as well. Pete Sale does a very nice job of grinding in one extra each side. It's nice and reliable and flows well.

[F5 Dave]

Yes that's the logical thing to do with the inlet port, I think a few people have come up with that independently. I did my old H with a dremel & a ball shapped bit, but you have to be careful not to port yourself into a shape that traps the bit.

[speedpro]

slow progress, or it could be because there's more to it than you might think. Finally got the adaptor spun up and carved chunks off the back so it'd fit in the case. Drilled holes, tapped a couple and hey presto, more or less ready to go. Interestingly I dummied it all up on a pair of H100 cases you see in the photos and then found the MB100 cases are different. The oil feed to the main bearing from the transfer area is different and I had to carve a new relief in the bottom. I've decided to cut off sections that aren't needed to mount the stator.

240607240608240609

[F5 Dave]

Well there's something. Never thought they were anything but the same cases. Why would 'onda change them?

[jasonu]

Well there's something. Never thought they were anything but the same cases. Why would 'onda change them?

Purely to mess with Bucketeers.

Nice looking work Mike.

[Skunk]

Interestingly I dummied it all up on a pair of H100 cases you see in the photos and then found the MB100 cases are different.

Weren't you listening when I told you they were different? :lol: Sketchy has found that out too. It's not just the mounting points that are different... Anyway - enough of my shit.

[speedpro]

Trimmed the adaptor plate to fit better. Didn't come out too bad considering it was done with the high speed grinder.
240887240886

[speedpro]

No real progress with #6. It is fully wired for an Ignitech and I'm waiting for the next shipment to arrive. Will start tuning with the 34mm carb and swap to the 36mm with TPS and solenoid powerjet later.
On another front, my plans for bucket domination with a fleet of MB powered buckets has taken the first step. Dave ran his more or less stock MB100 making 19.?hp in the Aprilia RS chassis in the weekend. In the first race starting from the 2nd row he finished 4th and reckons he wasn't even trying. He took it easy in the 2nd points race, starting at the back and just circulating to get about 15th he reckons. I have another MB engine on the bench for another rider. It has a few issues with the bore and piston which I've recovered(?) with emery tape and Drano. It'll be good enough for testing a few things before it gets rebored. My sons MB50 is coming along as well. It seems to run better now that I've reshaped the piston crown and dropped the cylinder about 2mm to get the squish about right and the ports where they should be. I've also brazed clamps to the top triple clamp and the front end is less flexible now and has been dropped down the forks for quicker steering. It needs to go further but we'll try it first.

[speedpro]

As per the ESE thread we've managed a few runs at 30.0hp. It didn't look like it was possible for a bit with a number of 29.9hp runs. Rob was doing the programming and I was running the throttle and in the end managed to find the .1hp. Rob has the technique for determing just what timing is required at which revs. Funnily enough using the Ignitech we have found that a fixed ignition advance is no real handicap and it is only at one point very high in the revs where it was actually any use to knock the timing back a couple of degrees. It's so easy to adjust and program, we just kept the engine running, made a change and did another run after slowing the back wheel and roller. The back brake completely went away and ended having no effect at all after a couple of runs.
The alternator is a bonus. As soon as the motor is turned the output is 14.4v. I only had the battery connected to initially program the Ignitech.
Next step is to try the 36mm carb.

246780

[F5 Dave]

Have been thinking about power for running a pump. What was the old ign? my RS one is not a good match as it has benefits when running advanced or retarded at different parts of the curve (not the most predictable ones in some cases).

[andrew a]

[QUOTE=speedpro;1130152881]As per the ESE thread we've managed a few runs at 30.0hp.



Well done. Thats a great effort. Total domination over those FXRs!

[speedpro]

Negotiations have begun with a couple of fast riders so there's a good possibility of a few FXR riders getting the "learn", especially as I'm now looking at fitting the motor into my RS125 chassis.

[koba]

Negotiations have begun with a couple of fast riders so there's a good possibility of a few FXR riders getting the "learn", especially as I'm now looking at fitting the motor into my RS125 chassis.

Jeeze man, we have to have some chance, a small sliver of hope somewhere!

[F5 Dave]

I think Mike's sized up the RS & realised he's never going to be able to shoehorn himself on it.

[Buddha#81]

I think Mike's sized up the RS & realised he's never going to be able to shoehorn himself on it.

When are the deluded going to relise the RS chassis is for 50kg teanages. All four of the RS buckets down here in chch are owned by people on the wrong side of 30.....fark two of them are over 40. Wake up people and stop trying to relive you youth!:facepalm:

[F5 Dave]

Yeah I fall well into that 2nd (er 3rd) group as well. & 30kg out of the first group. I've raised the seat 60mm & lowered the pegs a heap & just cope. Thing is, Gherkin is about a foot taller than me.

[jasonu]

Negotiations have begun with a couple of fast riders ...

I guess my invitation got lost in the mail???

But seriously folks, nice job Mike. I am looking forward to some videos and good results.

[richban]

Negotiations have begun with a couple of fast riders so there's a good possibility of a few FXR riders getting the "learn", especially as I'm now looking at fitting the motor into my RS125 chassis.

Please, none of them skinny fast kids. They don't need all that grunt. they have there youth and all that. Bring it down to BOB. That would be a proper test. well done.

[Buddha#81]

Bring it down to BOB. That would be a proper test.

What he said!

[speedpro]

What a great weekend at Taupo. Caught up with loads of people I haven't seen for ages. Big congrats to Pacific Motorcycle Club for a great meeting and accepting that the chicane should go.

For me it didn't start too well with a crash in the first practice where I nearly collected Skunk, and the bike all on it's own did smack into another rider. Thankfully he didn't go down. My knee hasn't changed colour but it's good and puffy. The bike ended with a punctured front slick, tweaked front end and damaged right peg. Henk lent me a slick off a bike that wasn't going any more and the rest was fixed over a few hours. I was a bit demotivated after the crash and was a bit sore. Finally had the bike working close to the start of the GP, by which time it was wet. Thankfully I had a spare set of wheels lent to me by TZ(S)350 along with a borrowed pair of wets. By the time I got them on everyone had already done a warmup lap so I just slotted in at the back of the grid. I'd never used wets before and just took off and followed a few others for a lap or so. It didn't take long to figure the tyres were gripping pretty good. I was accelerating out of the hairpin hard and it just stuck. I wasn't stupid enough to try and stay with Rich on the sweeper when he went past but they were pretty good. In the wet the engine temperature was staying around 60deg and was making lots of power. It was revving out cleanly and was a real buzz to ride. At the end I managed 9th, with Avalon in 8th right behind ready to lap me. The interclub challenge was nearly dry and the engine got up to 100deg so in the interests of not blowing it up I backed off for the last lap or two. Looks like I need a waterpump and possibly a bigger radiator. It definitely wasn't as crisp when hot so 60deg seems to be a running temp to aim for. This was also the first time the Ignitech and generator has been used seriously and they worked without missing a beat.

People who must be thanked -
ESE for letting me and ROB use their van
ESE(Cully) for letting me and Rob use the dyno and fill the workshop with blue smoke.
Rob for the road trip and the wheels and wet tyres I borrowed.
Henk for the front slick, even though I never actually used it.

Things learnt -
I need to go round corners faster,
failing that I need a faster bike,
the likelihood of beating anyone in front of me over the weekend, is zero or pretty close to it.

[Rick 52]

What a great weekend at Taupo. Caught up with loads of people I haven't seen for ages. Big congrats to Pacific Motorcycle Club for a great meeting and accepting that the chicane should go.


Things learnt -
I need to go round corners faster,
failing that I need a faster bike,
the likelihood of beating anyone in front of me over the weekend, is zero or pretty close to it.

Not sure about that Mike you had great pace in that last race and it was still damp in places !! In a dry race and with out a crash in the morning I think you could have been much further up the field ..and your bike smells great !what oil do you run ? I run motul 150mils 5lts 98oct standard pistons always plenty of oil when inspected.

[speedpro]

Oil is Elf HTX909 at 25:1 or 40mL per L.

I had been using Motul 800 at 40:1 for years or forever I don't quite remember but when I started running kart pistons at close to kart motor revs I decided to use what the kart shop guys use. It's supposed to be some sort of synthetic castor oil. So far the motor has always looked good when I've inspected it.

[speedpro]

New bit fitted. 36mm Keihin with TPS and electronic powerjet.251801251802251803251804

[koba]

36!!!

Fuck oh dear!

P.S. ever noted down the Crankcase volume of a std MB100...?

[Henk]

P.S. ever noted down the Crankcase volume of a std MB100...?

276 cc

Ten things

[F5 Dave]

mm, that seems more than big Henk.


Carb looks good, be interested to see how it runs & what sort of angle you can get away with. I have a 36PWK resting on some cases atm but the non TPS model as the RS shock sits to the left, just where the newer carb has it. I'll have to mount the TPS elsewhere. Either way it can wait, I don't have the pingas for an ignitech, just want to make sure I have the room.

[Henk]

mm, that seems more than big Henk.


Probably, I just took a wild arse guess to wind Koba up, surprised you didn't pick up on it.

[koba]

Probably, I just took a wild arse guess to wind Koba up, surprised you didn't pick up on it.

Your wild arse guess actually had some interesting results. I think I'm just going to have to measure what I have and derive a std figure from that. I guess if I can fill in the sections I have taken out with Plasticine or similar I should be able to back track to a rough figure for std.

[quallman1234]

Your wild arse guess actually had some interesting results. I think I'm just going to have to measure what I have and derive a std figure from that. I guess if I can fill in the sections I have taken out with Plasticine or similar I should be able to back track to a rough figure for std.

Fuck that, just do what you have atm and call that close enough to stock...

[F5 Dave]

Probably, I just took a wild arse guess to wind Koba up, surprised you didn't pick up on it.

yeah the maths for a 100cc cylinder was pretty obvious, i was wondering where you were going with that. If you'd said 850ml it would have been funny as its cast on the gbox filler.

[Henk]

Haven't looked closely enough at an MB100 motor to know that, after all two stroke engines are really only suited to gardening equipment.

[koba]

I'm playing with MOTA.

Kyle and I went 1/2s in it from the ESE guys.

The numbers I plug in as guesses actually seem to make quite a big difference.

I'm still learning and putting shit in to get shit out.
I'm mindful that it may not reflect reality 100%.

All interesting stuff though.

EDIT: Speedpro, sorry for the standard bucket forum thread hijack.

[Henk]

I'm still learning and putting shit in to get shit out.
I'm mindful that it may not reflect reality 100%.


EDIT: Speedpro, sorry for the standard bucket forum thread hijack.

Close is good enough surely.

And Speedpro, he's lying, he isn't sorry at all.

[speedpro]

Been playing with a laptop given to us by the sister-in-law. Fitted a USB-serial cable, loaded the software, and connected it to the Ignitech. I fed 12v to the ignition from a battery and it all connected just fine. I now have the programming that we did on the dyno safely stored away and have done a few changes to reflect the powerjet and TPS. It comes up with a funny looking ignition map by default when "3D" is selected so it'll be interesting to see how that compares with what the dyno tells us is needed.
I have been playing with another MB in the garage and found a big mismatch at the exhaust port flange and the pipe. The pipe was 5-6mm smaller diameter - no wonder it wasn't making any power. I've fitted a proper slip-joint and fitted a copy of the good pipe for my motor. With the exhaust port mods I've done it'll be real interesting on the dyno.

[F5 Dave]

yeah its real easy to get those ex ports to flare out without trying. My last RS125 pipe I tried to bring in as 40mm was waay too big. Std MBs are ~32 so the question is where to run them with the std single port. I've tried my new pipe at 34 to try the small end of the scale.

[jasonu]

[QUOTE=speedpro;1130208205]
I have been playing with another MB in the garage and found a big mismatch at the exhaust port flange and the pipe. QUOTE]

My and Picketts 1991 RS125's both had ex port outlets that didn't fully match the exhaust flange. The flange was bigger in some places. We decided Mr. Honda knew more than us so we didn't touch it.
However, 'Ride 'em 'till they blow' Owen Wilson ground his ex port outlet to match the flange and made his bike slower.

[F5 Dave]

yeah the RS125 step has been widely covered. The MB has one, but it is used in production to locate the pipe that seals up into it so there is no step, just a small port, which is fine for its intended porpoise of carrying around a small Asian family & their chickens/goats etc.

[speedpro]

yeah its real easy to get those ex ports to flare out without trying. My last RS125 pipe I tried to bring in as 40mm was waay too big. Std MBs are ~32 so the question is where to run them with the std single port. I've tried my new pipe at 34 to try the small end of the scale.

Just to clarify - I did not alter the "outlet" of the exhaust port. It was just a very poor setup as delivered. The port has been altered by someone so that there is no step. The outlet is the same size as the stock exhaust gasket. At the cylinder wall the port shape is a bit different in an effort to get blowdown T/A without exceeding exhaust T/A reccommendations.

[koba]

yeah the RS125 step has been widely covered.

The very day after I spent hours getting my pipe to line up very closely to the port.

Still, I'm glad I did it by manipulating the pipe rather than the still untouched (Fully!) exhaust port.

I need to start building a proper pipe. Among other things, the inlet was too small on the one I adapted. I got around that by adding a small section that I flared out with a large ball-pein hammer. The matching mentioned above was lots of welding and grinding inside the ring that the clamp bears on.

[TZ350]

yeah its real easy to get those ex ports to flare out without trying. My last RS125 pipe I tried to bring in as 40mm was waay too big. Std MBs are ~32 so the question is where to run them with the std single port. I've tried my new pipe at 34 to try the small end of the scale.

32 might be right ...... There are some graphs and pics from the simulator on my original post.


I have been looking at exhaust port nozzels, now I would have thought the best arrangement was to have the exhaust port gently opening up starting at the port window.

But EngMod2T and Wobbly tell me that a nozzel shape is what I need for top end and over rev.


I have done some tinkering with the simulator and a 34.5 nozzel opening up to 40mm to match the pipe is the optimum setup for my 125.

[F5 Dave]

Been playing with a laptop given to us by the sister-in-law. Fitted a USB-serial cable, loaded the software, and connected it to the Ignitech. I fed 12v to the ignition from a battery and it all connected just fine. I now have the programming that we did on the dyno safely stored away and have done a few changes to reflect the powerjet and TPS. It comes up with a funny looking ignition map by default when "3D" is selected so it'll be interesting to see how that compares with what the dyno tells us is needed.
. . .
Just thought about this the other day. Presumably if you have previously got a setup that does its best to extend over rev by advancing the ignition, - you may have to back this off before playing with turning the PJ off cutting fuel & then re-find the curve later- lest you heat it up a bit too much.

[F5 Dave]

Hey Mike, what stator are you using? had a quick squizzy at CRF250s on Evilbay & they all appear to be inside out jobbies with stator mounting on the outer engine case.

Thinking about how to power my waterpump. Not sure if it would drive my current ign. Does stator set have puls coil & charge coil? (I can see the pulser coil) Or just meant for totally electronic ign as it looks?

[speedpro]

Interesting day at the track. With the waterpump the temperature is staying low. I've taped up the radiator a little which brought the temp up to 55 on my gauge. The motor is staying crisp, possibly a little too crisp on the kart track. I've also got some other tyres fitted and it handles differently now. I was running up curbs at the start and generally wobbling round more than usual. Also after riding the scooter for weeks going to work it is real strange riding the bucket, the bars feel like they are bolted to the axle initially and it takes a bit to change the riding technique to match the riding position. My previously damaged right wrist was near useless after the first session. Anyway, the pump seems to be a good mod but it will be more obvious at somewhere like Taupo.

256213 256214 256215 256216

[Pickle]

so with the water pump do you have to turn it on manually or it comes on when the motor is running, I seem to remember popping pistons on the sidecar when someone forgot to turn the water pump on !!!!

[speedpro]

I've had that discussion with someone else already. Currently there is a switch as I don't want the electrical load when I'm starting the bike as there is no battery, just the alternator, reg/rec, and capacitor.

Subject change: - our old sidecar is coming back to Auckland. Sidecars are making a bit of a resurgence. Evidently the waterpump is now driven off the ignition rotor nut. I'm hoping to be able to bludge a ride, that would be cool.

Another subject: - "world domination of bucket racing with a fleet of MB powered buckets" - Gary got a 3rd and 1st today on his and I don't think he was trying too hard. Only a playday though. Tokoroa should be fun next weekend with both Gaz and Dave M riding, and Rick though he has some pussy Suzuki motor.

[wildman]

I've had that discussion with someone else already. Currently there is a switch as I don't want the electrical load when I'm starting the bike as there is no battery, just the alternator, reg/rec, and capacitor.

Subject change: - our old sidecar is coming back to Auckland. Sidecars are making a bit of a resurgence. Evidently the waterpump is now driven off the ignition rotor nut. I'm hoping to be able to bludge a ride, that would be cool.

Another subject: - "world domination of bucket racing with a fleet of MB powered buckets" - Gary got a 3rd and 1st today on his and I don't think he was trying too hard. Only a playday though. Tokoroa should be fun next weekend with both Gaz and Dave M riding, and Rick though he has some pussy Suzuki motor.

If it works out sidecar should be in Auckland for April meeting at Mt Welly

With your elec water pump you could set the earth lead up through an air con thermo switch, they're fairly small and can be adjusted to switch on at different temperatures. We've used them for switching on cooling fans on vehicles, only hassle is getting water hose to seal with capillary tube in it

[F5 Dave]

That water pump looks like a gallery tap water delivery pump.


oh yeah I worked out the X model is the enduro one the R is MX.

[husaberg]

That water pump looks like a gallery tap water delivery pump.


oh yeah I worked out the X model is the enduro one the R is MX.

Now how pray tell, did you figure that one out Dave?

Someone telling you it was a X model must have been a good start?:innocent:

[F5 Dave]

yeah thanks for that, but Honda still has a silly name for the CRF250 with the suffix determining if it is the enduro model or MX.

How hard would it have been to call it a CRX250? or CXR, or CXX? or XRF ar any other range of letters.

Mind you Yam had confusion when they introduced their 4 stroke YZ range as they had already used YZF for thier road bikes.

[husaberg]

yeah thanks for that, but Honda still has a silly name for the CRF250 with the suffix determining if it is the enduro model or MX.

How hard would it have been to call it a CRX250? or CXR, or CXX? or XRF ar any other range of letters.

Mind you Yam had confusion when they introduced their 4 stroke YZ range as they had already used YZF for thier road bikes.

WR as well are a bit confusing different motors depending on last letter. not to mention 2 and 4 stroke

Speedpro
Did you move the Powerjet on the KX shorty carb?
Wob mentioned something about that?

[speedpro]

What fun Tokoroa was. That track is nothing like what it looks like on Google or the Youtube vid. My bike was hauling arse well enough that it wasn't worth checking the jetting even though it was surely a bit rich. In the end it came to a reasonably sudden stop(plug chop) so I have checked the plug and it was rich so possibly should have been a bit faster. Didn't matter as it went as fast as it was going to go with me on it. The temp stayed at about 55-60deg with the pump running and with 2 strips of duct tape across the bottom of the radiator so there's about 25% cooling capacity in reserve. It definitely likes being a bit cooler than previous. It was nice and crisp all over and shot between corners with only a little dab at the clutch sometimes

The other two MB/H100 engined bikes went OK though they looked a whole lot better because of Dave and Gary riding them. Gary's bike has no plug gap now so it'll be interesting to have a look inside. Both engines are what I consider to be baseline considering what had already been done to them and I really only intended to get them going reliably before proceeding with a proper tuneup. Only 1 out of 2 so far. I kept telling Gary to thrash his bike as hard as he liked as he wouldn't be able to blow it up, I may have to revise that advice. Honestly though I don't know why it stopped. When I got the engine I did use Draino on the cylinder to get the smeared aluminium off the bore followed by emery tape for the bore and piston to remove the worst of the scores but it shouldn't have stopped, maybe just been a bit slower. On the dyno it only revved to about 11-12,000rpm so plenty safe for one of these engines.

I'm having a few days off work. Seems I might have tweaked my neck/ribs a bit and there may also be a bit of nerve tickling going on. There's funny crunching noises I can hear in my head when I move my neck and the odd pop from my shoulder/rib area though no broken bones. I stopped into the Emergency department at the local hospital to be greeted by my name. Turns out the nurse on the counter used to be the AMCC medical advisor/organiser when I was on the road race committee. Rather than a 4 hour wait to be seen we had a good chat in an adjoining room and she checked me out to confirm I'd survive till the next day and to go see my own doctor. Thanks very much to Annemarie - very much appreciated.

[F5 Dave]

I have a super reasonable brand new std bore MB100 piston & rings on my desk here.

[speedpro]

Nice of you to offer, but 2mm clearance is probably getting a bit on the loose side. A nice brand new crank would likely be of more interest. There has been a little interest expressed in a run of offset big end pins. It's getting tempting to check out current costs for say a run of 5. Throw in a (legal)rod kit and a bit of crank machining and it could still end up being quite expensive but you save by using cheap KT100 pistons and being able to step up in .05mm steps extending the life of each cylinder.

[husaberg]

Nice of you to offer, but 2mm clearance is probably getting a bit on the loose side. A nice brand new crank would likely be of more interest. There has been a little interest expressed in a run of offset gudgeon pins. It's getting tempting to check out current costs for say a run of 5. Throw in a (legal)rod kit and a bit of crank machining and it could still end up being quite expensive but you save by using cheap KT100 pistons and being able to step up in .05mm steps extending the life of each cylinder.

Offset gudgeon are you meaning crankpins?

Did you check the scooter ones i posted a while back against the STD mb/H100

Actually the T5 eccentric pin looks like it could work with limited mods as its only 2mm short

The width at the big end is workable? with thinner thrust washers

Rod the right length but the little end is to big, so bugger.

http://www.sip-scootershop.com/en/products/crankshaft+pin+eccentric+pin_4043ad213

http://www.sip-scootershop.com/en/products/crankshaft+pin+drt+eccentric_4043ad179 (http://www.sip-scootershop.com/en/products/crankshaft+pin+drt+eccentric_4043ad179a)

(http://www.sip-scootershop.com/en/products/crankshaft+pin+eccentric+pin_4043ad213)
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[cotswold]

Another subject: - "world domination of bucket racing with a fleet of MB powered buckets" - Gary got a 3rd and 1st today on his and I don't think he was trying too hard. Only a playday though. Tokoroa should be fun next weekend with both Gaz and Dave M riding, and Rick though he has some pussy Suzuki motor.[/QUOTE]

You may want to talk to Av and ask her to slow down a bit:laugh:

[F5 Dave]

Nice of you to offer, but 2mm clearance is probably getting a bit on the loose side. A nice brand new crank would likely be of more interest. There has been a little interest expressed in a run of offset big end pins. It's getting tempting to check out current costs for say a run of 5. Throw in a (legal)rod kit and a bit of crank machining and it could still end up being quite expensive but you save by using cheap KT100 pistons and being able to step up in .05mm steps extending the life of each cylinder.
yeah I'd still be keen.

[speedpro]

F5 was saying about a problem he had with clutch slip and a problem with incorrect springs. Up till then I'd always assumed mb5s and MB100s used the same springs and never took any notice. I've now measured them up and found the MB100 springs are about 2mm longer but wound with thinner wire, about 2.7mm versus 3mm. I had been keeping sets together and the MB5 clutch pack I have had 4 short springs and the MB100 clutch packs both had longer thinner springs. Gary has had an engine problem so I'll be checking the springs in his clutch once I have it out.

Gary's bike died at Tokoroa in the last race. I've found two little pieces of steel in the exhaust port and in the pipe. Both have obviously been through the engine with clear marks on the head and piston. The big end "looks" OK and the little end is fine. The piston has been hammered good enough to trap the ring tight. The gearbox oil has come out black and horrible so I'll need to check what's up with that. The crank rotates freely but there is a very faint crunchy noise and feel about it. The bike died because a piece of steel pushed the plug gap closed which probably saved it from further mayhem.

[Yow Ling]

. The crack rotates freely but there is a very faint crunchy noise and feel about it.

Any free crack sounds dodgy to me

[speedpro]

Finally got the ignition rotor off Gary's crankshaft and got the cases apart. It isn't pretty. Stock bearings are good for all sorts of revs and I have never had one let go, on a MB. The amazing thing is the motor was still running sort of OK. The bearing is shagged, bits have been fed through the motor, the seal to the gearbox is not good and is probably where the crap got into the gearbox oil which is black and crappy, and the ring is trapped in the groove. Seems like it's time for a refresh, new piston, nice straight clean bore, and a couple of nice new C3 bearings, and new seals.

257603257604257605257606

[husaberg]

Finally got the ignition rotor off Gary's crankshaft and got the cases apart. It isn't pretty. Stock bearings are good for all sorts of revs and I have never had one let go, on a MB. The amazing thing is the motor was still running sort of OK. The bearing is shagged, bits have been fed through the motor, the seal to the gearbox is not good and is probably where the crap got into the gearbox oil which is black and crappy, and the ring is trapped in the groove. Seems like it's time for a refresh, new piston, nice straight clean bore, and a couple of nice new C3 bearings, and new seals.

257603257604257605257606
I have but it was a crap bearing obviously assembled by a cheapskate non C3.
I am kind of surprised it wasn't hammering the ignition?

[Buckets4Me]

Finally got the ignition rotor off Gary's crankshaft and got the cases apart. It isn't pretty.

do you know how many pistons that engine has eaten ?

i belive it's a few

[bucketracer]

The amazing thing is the motor was still running sort of OK. The bearing is shagged, bits have been fed through the motor, the seal to the gearbox is not good and is probably where the crap got into the gearbox oil which is black and crappy, and the ring is trapped in the groove. Seems like it's time for a refresh, new piston, nice straight clean bore, and a couple of nice new C3 bearings, and new seals.

Main brg fails, bits of metal through the motor and still the 2-stroke was running, sort of. New Brgs, piston and a re bore and its racing again, strokers sound pretty robust to me........ compared to those rather fragile and expensive 4-strokers.

[speedpro]

With the crank out I've found the big end pin isn't central in the crankshaft but is a good 2mm to one side. I haven't measured it but there seems to be a lot of clearance between the rod and crank wheels. Not good.

[Hilleye]

Main brg fails, bits of metal through the motor and still the 2-stroke was running, sort of. New Brgs, piston and a re bore and its racing again, strokers sound pretty robust to me........ compared to those rather fragile and expensive 4-strokers.

As long as it crosses the finish line it can still win.

[speedpro]

I've been looking for a good big end bearing for Gary's bike. Whilst at the kart shop I checked out a KT100 rod kit. Turns out the big end bearing is 26X20X13.8, EXACTLY the same as a MB100. Moral dilemna for a bit. They are a bit different to look at and I could spot one even if it was all assembled onto the crank/rod. Further research has come up with a same size bearing with a description that makes it similar design to the KT part. Moral dilemna over. It does mean if you wanted to build a cheater engine which handled 16,000rpm that the parts are available from your local kart shop.
Just in case anyone thinks I honestly thought for more than a second about using an illegal bearing, anyone is welcome to have a look inside my engine, or Gary's but you'd have to ask him about pulling his one apart.

[kel]

I've been looking for a good big end bearing for Gary's bike. Whilst at the kart shop I checked out a KT100 rod kit. Turns out the big end bearing is 26X20X13.8, EXACTLY the same as a MB100. Moral dilemna for a bit. They are a bit different to look at and I could spot one even if it was all assembled onto the crank/rod. Further research has come up with a same size bearing with a description that makes it similar design to the KT part. Moral dilemna over. It does mean if you wanted to build a cheater engine which handled 16,000rpm that the parts are available from your local kart shop.
Just in case anyone thinks I honestly thought for more than a second about using an illegal bearing, anyone is welcome to have a look inside my engine, or Gary's but you'd have to ask him about pulling his one apart.

Have you sized up the AM6 rod and bearings? I know they have all manner of rod lengths with differing big and small end pins and of course the AM6 (OEM or after market) are all legal as they're after market parts for a road going engines. I seem to remember the Metrakits rev to 14.5k all day long.
I guess the real question is why aren't you coming to TePuke and will you have Gary's motor back together in time?

[husaberg]

I've been looking for a good big end bearing for Gary's bike. Whilst at the kart shop I checked out a KT100 rod kit. Turns out the big end bearing is 26X20X13.8, EXACTLY the same as a MB100. Moral dilemna for a bit. They are a bit different to look at and I could spot one even if it was all assembled onto the crank/rod. Further research has come up with a same size bearing with a description that makes it similar design to the KT part. Moral dilemna over. It does mean if you wanted to build a cheater engine which handled 16,000rpm that the parts are available from your local kart shop.
Just in case anyone thinks I honestly thought for more than a second about using an illegal bearing, anyone is welcome to have a look inside my engine, or Gary's but you'd have to ask him about pulling his one apart.

I thought you had a larger Big end than std say 22mm or so. I will understand if its a Secret mind you:scratch:

[speedpro]

Correct, 22mm big end in my bike.

I'm not going to Te Puke. Looking at the budget, keeping the wife happy(ish), and still not right after Tokoroa. Still got a neck that makes crunchy sounds when I move it and ribs that still aren't attached to vertabrae properly.

Gary's bike is being repaired at a leisurely pace and will be some time before it's going again. That said the crank is at the kart shop to be disassembled and checked over. If needed we'll get some new bits and reassemble it properly.

[speedpro]

The word on the crank is that the motor stopped just in time. The big end cage had a break. There's something up with the pin as well and it needs to be replaced. Sensible thing to do is throw a rod kit at it.

[speedpro]

All the bits for Gary's bike are with the kart shop and being reassembled or bored so it's only a matter of time until it's back together.

Call me slow but I've only just had a brilliant idea. A KT100 piston fits in an MB100 engine really nicely, but with a stock crankshaft the engine capacity ends up over 105cc so you end up being restricted to a 24mm carb and aircooling. Rather than spend money on a new crankpin to reduce the stroke and get the capacity down, why not use a Team ESE plenum chamber and a modified 24mm carb. It solves so many problems. Using a straight rubber carb mount a straight velocity stack can be mounted on the reed block being fed from the plenum. This will give the perfect inlet tract for the engine being fed from the plenum for practically no restriction, less than a carb anyway. The carb can then be placed wherever it will fit on the bike and plenum. This could be a good way of getting round the problem of fitting carbs on MB engines fitted to other frames like RS's etc. The air cooling might be a bit of a handicap but with the big copper fins like ESE use it won't be all that bad. Air cooling may be a bit of a problem at something like a GP at Taupo but recently it hasn't been an issue and probably won't be this weekend either. Careful design should avoid the problem with the fuel/oil pooling in the bottom of the plenum. An engine with this configuration should be good for 30hp if it's built right and not cost much at all beyond the cost of the usual rebuild and some porting.

[husaberg]

All the bits for Gary's bike are with the kart shop and being reassembled or bored so it's only a matter of time until it's back together.

Call me slow but I've only just had a brilliant idea. A KT100 piston fits in an MB100 engine really nicely, but with a stock crankshaft the engine capacity ends up over 105cc so you end up being restricted to a 24mm carb and aircooling. Rather than spend money on a new crankpin to reduce the stroke and get the capacity down, why not use a Team ESE plenum chamber and a modified 24mm carb. It solves so many problems. Using a straight rubber carb mount a straight velocity stack can be mounted on the reed block being fed from the plenum. This will give the perfect inlet tract for the engine being fed from the plenum for practically no restriction, less than a carb anyway. The carb can then be placed wherever it will fit on the bike and plenum. This could be a good way of getting round the problem of fitting carbs on MB engines fitted to other frames like RS's etc. The air cooling might be a bit of a handicap but with the big copper fins like ESE use it won't be all that bad. Air cooling may be a bit of a problem at something like a GP at Taupo but recently it hasn't been an issue and probably won't be this weekend either. Careful design should avoid the problem with the fuel/oil pooling in the bottom of the plenum. An engine with this configuration should be good for 30hp if it's built right and not cost much at all beyond the cost of the usual rebuild and some porting.
If you talk to Grumph he has done a 54mm(cr125 piston i think) for Kevin Orr ,(Yes everyone says they don't do that big i know but it appears they do) he might even part with the cylinder as Kevin i think preferred the 100cc one then you could also put the pin 180 degrees out and........... either that or the Athena one for the MB8 goes to 57mm and CR125 pistons can be used again................

[Grumph]

Nah, Kev's parked the Hondog up as a piece of historic memorabilia now. The big motor was somewhat more torquey but was only put together as a proof of concept trial and never developed. Spending most of the year in Oz will do that.
It was pretty historic at last Greymouth anyway - front slick 13 years old, rear, 14....tyres, they're all in the mind.....
Academic anyway as he did most of his passing in the gutter.
Went out well though - first 2 stroke home each time.

I suspect he's hoping I'll come up with something trick for him - or he'll buy something off trademe and it'll turn up here to be prepped.

[husaberg]

Nah, Kev's parked the Hondog up as a piece of historic memorabilia now. The big motor was somewhat more torquey but was only put together as a proof of concept trial and never developed. Spending most of the year in Oz will do that.
It was pretty historic at last Greymouth anyway - front slick 13 years old, rear, 14....tyres, they're all in the mind.....
Academic anyway as he did most of his passing in the gutter.
Went out well though - first 2 stroke home each time.

I suspect he's hoping I'll come up with something trick for him - or he'll buy something off trademe and it'll turn up here to be prepped.

Was i right on the bore and the source of pistons? I did think you were having an Mb100 clearing sale though?

[Grumph]

Shit, it was more than four years ago now I built that motor...I think it was a wiseco CR125 piston.

Dave was the beneficiary of the parts clearout

[F5 Dave]

I think he told me it was 54.5 CR oversize, but shit it was more than 4 months ago.

[Skunk]

Call me slow but I've only just had a brilliant idea. A KT100 piston fits in an MB100 engine really nicely, but with a stock crankshaft the engine capacity ends up over 105cc so you end up being restricted to a 24mm carb and aircooling. You are slow but with a quick bike...
Why not increase the 100cc overbore limit to 106cc from 104cc and stop all the expense and stuffing about. Might see a few more 2 smokes at the track instead of FXRs. :brick:

[speedpro]

You are slow but with a quick bike...
Why not increase the 100cc overbore limit to 106cc from 104cc and stop all the expense and stuffing about. Might see a few more 2 smokes at the track instead of FXRs. :brick:

That's the whole point of my post, going oversize saves a barrel and is cheaper when using KT100 pistons and with a plenum you aren't disadvantaged by having to use a 24mm carb. Building a plenum isn't a whole lot of stuffing about either.
Plus from what Rob says you get some pretty impressive fireworks when it pops back in the plenum with flames coming out all around the place.

[F5 Dave]

isn't confirmed that a 24 won't still be a restriction with a plenum or that it won't hurt throttle response. Or is it?


106.2 would help TS100, TF100, GP100, MB100, H100, A100 & possibly others.

Have to change
F4 2 stroke engines over 106.2cc are restricted to carburation equivalent to a single 24mm carburettor - else it won't help much.

[F5 Dave]

. . .
Plus from what Rob says you get some pretty impressive fireworks when it pops back in the plenum with flames coming out all around the place.
Doesn't any of that sound a tiny bit dangerous?:blink:

[richban]

Doesn't any of that sound a tiny bit dangerous?:blink:

why not develop a plenum on the other side of the carb like everyone else. Out there I know.:innocent::innocent::innocent:

[Yow Ling]

isn't confirmed that a 24 won't still be a restriction with a plenum or that it won't hurt throttle response. Or is it?


106.2 would help TS100, TF100, GP100, MB100, H100, A100 & possibly others.

Have to change
F4 2 stroke engines over 106.2cc are restricted to carburation equivalent to a single 24mm carburettor - else it won't help much.

To keep the change fair , maybe some compassion could be shown to the diesel brigade by allowing then 160 cc , then everyone benifits .

[richban]

To keep the change fair , maybe some compassion could be shown to the diesel brigade by allowing then 160 cc , then everyone benifits .

I think that if the rules change it should be thought through proper like. Trade experts together from either camp talking it through. Otherwise its just people trying to make up rules for there own gain. Its gotta be fare and all.

[F5 Dave]

The 4 bangers just got a capacity increase a few years back. From 140 to 150 (155 for rebores) & then later 158.09 for rebores. 100s have been the same for eons.

[Grumph]

I think that if the rules change it should be thought through proper like. Trade experts together from either camp talking it through. Otherwise its just people trying to make up rules for there own gain. Its gotta be fare and all.

My god man, has no one ever explained to you how MNZ rules are established ? Go to a conference as an observer...warning - you'll need a strong stomach. the "workshops" which put the agreed versions through to the main conference are late night boozy arguments where every possible axe is ground and the strongest prevail - the weak go to the wall. Months of training in drunken arguments are required to qualify as a delegate...

That said - the current rules aren't too bad. I know you'd like to have more overbores available but let's face it, most would go straight to the max bore allowable anyway. Kev's "big" MB used a venturi shaped restrictor downstream of the slide and with development would have been up with the Hoogie's bikes based on Greymouth. Wasn't that much slower as it stood.

[TZ350]

We now know 28rwhp can be sucked through a legal but cleverly modified 24mm carb, and the plenum idea might help push it past 30. Mikes ideas fit within the rules as they are and he suggests a way of making a cheapish MB100 that could touch 30rwhp using a 52mm KT100 piston and no expensive crank pin or special parts. With a bit of copper to aid air cooling its all pretty much something anyone can do. But the FXR's have shown that Hp is not everything.

I think the rules work pretty well as they are.

[jasonu]

You are slow but with a quick bike...
Why not increase the 100cc overbore limit to 106cc from 104cc and stop all the expense and stuffing about. Might see a few more 2 smokes at the track instead of FXRs. :brick:

And then the H20 100cc crowd will say 'increase the max capacity to 110cc as it saves me a cylinder'. Then the aircooled 125cc mob will want 135cc and the coal burner crowd will want 160cc.
Bag of worms I say.

[husaberg]

We now know 28rwhp can be sucked through a legal but cleverly modified 24mm carb, and the plenum idea might help push it past 30. Mikes ideas fit within the rules as they are and he suggests a way of making a cheapish MB100 that could touch 30rwhp using a 52mm KT100 piston and no expensive crank pin or special parts. With a bit of copper to aid air cooling its all pretty much something anyone can do. But the FXR's have shown that Hp is not everything.

I think the rules work pretty well as they are.


Yeah can of worms but i should add. We know that 28rwhp can be sucked through a 24mm venturi carb with 125cc
he would still be handicapped quite a few cc's if you catch my drift.
Dave made a point above re the rules with cc increase only for the 4 strokes plus the tweeking for the 125cc ac's.
but forgot they also got a hike from 130.5cc as well. Food for thought, or fought fodder?or aimless talk that never goes nowhere. It will cost me plenty to debore and destroke Vanessa, but shit happens (Unless i am doing it then stuff all happens- till the last minute then panic stations.)
but 50mm or so are not that cheap or easy to find kart ones are cheap plentiful and a couple of cc to big, Life sucks. Murphy drafted the rules.

[speedpro]

The rules don't need to be changed. Look at the GP this weekend. Who is going to win on what bike? Every combination allowed by the rules is in with a chance
except those pesky 4-stroke things

[bucketracer]

... plus the tweeking for the 125cc ac's....

What was the rule tweeking for 125cc ac's?

[husaberg]

What was the rule tweeking for 125cc ac's?

The 125cc 24mm carb 2t rule never used to exist. It used to be 2 stroke to 103.5 or so, four strokes to 130.5cc with 100cc or there abouts prob 103,5cccc supercharged/turbo charged for F4, tweak may not be the correct term.But i like it:drool:(Thoughts and opinions discussed by Husaberg may differ from the opinions expressed by Mrs Husaberg)

[speedpro]

Luckily I made the 4-stroke comment in really small letters. Have dismantled the motor and it isn't looking good. It could easily have been a LOT worse as the following pictures show. The piston had smeared itself up the bore but not too badly, more of a good rub for a lot of its circumference. There is an obvious crack in the crown which extends down to the gudgeon pin hole. When I inspected it more closely there is 8 or so other cracks including in the other gudgeon pin area. There are cracks above and below the pin boss. To me it doesn't look to be a tuning problem. Basicaly Dave did a plig chop and it doesn't look too lean though the pipe is pretty light in colour just down the header. The other thing of concern is the little end bearing. It was all there when dismantled but in a few more pieces than when I put it in. The crank will definitely be coming apart to check the big end.
260451 260452 260453 260454 260455 260450

[husaberg]

Luckily I made the 4-stroke comment in really small letters. Have dismantled the motor and it isn't looking good. It could easily have been a LOT worse as the following pictures show. The piston had smeared itself up the bore but not too badly, more of a good rub for a lot of its circumference. There is an obvious crack in the crown which extends down to the gudgeon pin hole. When I inspected it more closely there is 8 or so other cracks including in the other gudgeon pin area. There are cracks above and below the pin boss. To me it doesn't look to be a tuning problem. Basicaly Dave did a plig chop and it doesn't look too lean though the pipe is pretty light in colour just down the header. The other thing of concern is the little end bearing. It was all there when dismantled but in a few more pieces than when I put it in. The crank will definitely be coming apart to check the big end.
260451 260452 260453 260454 260455 260450

Prolite or MB100 little end Mike?

[speedpro]

The bearing is out of the ProX catalogue. It was a while ago but I seem to recall it was a slightly odd one to fit the rod and pin and also the KT100 piston, I'll have a note of it somewhere though it's easy to measure and order a new one. Might try for a better one next time. There are some good marks on the inside of the gudgeon pin bosses where the cage has rubbed. It would be good if somebody could shine a bit of light on possible causes. There is the same amount of wear on both sides. I've used Draino to take all the alloy off the bore so it's just a matter of dropping it at the kart shop now. It has a 52.15mm piston so will probably end up with a 52.2mm bore next.

[F5 Dave]

more rollers might be nice.

Lucky to catch that before it spat the pins out.

[bucketracer]

The rules don't need to be changed. Look at the GP this weekend. Who is going to win on what bike? Every combination allowed by the rules is in with a chance
except those pesky 4-stroke things

"those pesky 4-stroke things" .... :facepalm: at least it was in small print.

[husaberg]

The bearing is out of the TKRJ catalogue. It was a while ago but I seem to recall it was a slightly odd one to fit the rod and pin and also the KT100 piston, I'll have a note of it somewhere though it's easy to measure and order a new one. Might try for a better one next time. There are some good marks on the inside of the gudgeon pin bosses where the cage has rubbed. It would be good if somebody could shine a bit of light on possible causes. There is the same amount of wear on both sides. I've used Draino to take all the alloy off the bore so it's just a matter of dropping it at the kart shop now. It has a 52.15mm piston so will probably end up with a 52.2mm bore next.

I am guess by slightly odd it would correspond to the std Honda OD and ID?

My gut tells me the limit of the std style generic bearing has been reached (assuming there is no sign of localized overheating from lack of lubrication which is a reason as well for wrist pin failure.) A solid cadge would of course be better. but is it available in a size to suit if it is an odd one.? Kind of like these but the right size.
http://www.pvlsverige.se/vrm/Vevstakar/121815.jpgorhttp://www.pvlsverige.se/vrm/Vevstakar/JA-PI-21C.jpg
What sort of Hours or miles on the piston and wrist pin?

[speedpro]

Pressed the good crank apart tonight, thanks Rob and ESE, and it still looks good. Obvious wear but nothing to worry about. I'll order some flat silver plated bearings and new thrust washers and put it back together.

I've pressed a couple of other MB100 cranks apart as well. As a minimum they'll get fresh bearings and thrust washers. If anyone is interested I could build up custom cranks in exchange for your old one. I can rebalance them so they're usable in a motor without the balance shaft just like in my 30hp engine, and/or make one with a longer rod. I've found someone I trust to do a good job making whatever crankpins I need as well so if there is enough demand I could get a batch made. On that note I still think using a rod kit with say a 22mm crankpin and offset boring the crankweb holes to increase the stroke 2mm is a good idea and then using kart pistons. You'll be stuck with aircooling and a 24mm carb but it doesn't seem like it would be too big an issue. Cranks could be supplied with new main bearings as well, C3 unless you have a preference.

It also looks like I will be making 2 watercooled heads. If anyone is interested let me know and I'll get the lot done together.

One of the bikes I'm building needs a good pipe which I'll probably go to Wobbly to design and lazer cut. Not too sure about the final spec yet but probably aiming for say 25hp at 11-12,000rpm. I've tried "my" Wobbly pipe for the 30hp engine on this bike in the early dyno runs and it made 2hp more through the mid range and maybe 1hp more at the top and it was completely mismatched to the motor so a more compatible design can only be better.

I'm feeling better after the GP now, getting busy in the shed, working on my scooter as well. Until the wife finds out anyway.

[F5 Dave]

So to get to 104cc with a 52mm piston you only need to destroke 0.6mm or offset 0.3, or is memory serving me badly? stroke is 49.5 stoke, so 48.9 is under 104cc.

Is it feasible to weld & rebore 0.3 off. Not taking much out of the centre if you don't put a 22 pin in it. But 20mm pin leaves you with a 100mm MB rod unless can find something else decent.

But yes let me know, I need to get something sorted for my next bottom end.

[kel]

I'm feeling better after the GP now
Me too. :crybaby: well almost

[bucketracer]

So to get to 104cc with a 52mm piston you only need to destroke 0.6mm or offset 0.3, or is memory serving me badly? stroke is 49.5 stoke, so 48.9 is under 104cc.

Is it feasible to weld & rebore 0.3 off. Not taking much out of the center if you don't put a 22 pin in it. But leaves you with a 100mm rod unless can find something else decent.

But yes let me know, I need to get something sorted for my next bottom end.

Volume = PiexR2xH ... volume equals pie times radius squared times height.

Volume = PiexD2/4xH ... because R2=D2/4

Bore = 52mm and Stroke = 49.5mm

To get the answer in cc use cm ie 52mm = 5.2cm

Pie x Bore x Bore x Stroke all Divided by 4 = Volume

(3.1416 x 5.2 x 5.2 x 4.95) / 4 = 105cc

Re arranging for stroke, volume (0.104L) in liters to get mm

(4 x 0.104) / (3.1416 x 5.2 x 5.2) = 48.97mm or 49mm

So 49mm stroke and 52mm bore gives you 104cc

And a 48.5mm stroke gives you 103cc

[F5 Dave]

Yes I can do the math, I couldn't reliably remember if it was 49.5 stroke as I was bashing away. [edit, yes it is]


The maximum capacity for rebored engines shall be:
F4 2 stroke 55-100cc - 104cc

so can run up to 104cc

52 bore & 49 stroke gives a knats bollock over 104 which is why I suggested 48.9mm

[speedpro]

My offset pin gives a 48mm stroke allowing pistons up to about 52.7mm to be used. .75mm offset = 1.5mm change in stroke. With it in so stroke is increased and with larger pistons that will fit capacity goes to about 115cc or a bit more if you want to push limits with the thickness of the cylinder

[F5 Dave]

Are there any KT pistons that go more than 52? Thought they were clamped on size bar tiny clearance versions

Has anyone tried weld & bore?

[jasonu]

Yes I can do the math, I couldn't reliably remember if it was 49.5 stroke as I was bashing away. [edit, yes it is]


The maximum capacity for rebored engines shall be:
F4 2 stroke 55-100cc - 104cc

so can run up to 104cc

52 bore & 49 stroke gives a knats bollock over 104 which is why I suggested 48.9mm

But if you do all that hard and expensive work and later need to rebore would you not be fucked as you will go over the allowable 104cc limit unless you get rid of the water cooling and get a 24mm carb?

[F5 Dave]

or you just plate it. Apparently the NZ place does steel, but US chrome did my 50 about 7 years ago.

[husaberg]

Volume = PiexR2xH ... volume equals pie times radius squared times height.

Volume = PiexD2/4xH ... because R2=D2/4

Bore = 52mm and Stroke = 49.5mm

To get the answer in cc use cm ie 52mm = 5.2cm

Pie x Bore x Bore x Stroke all Divided by 4 = Volume

(3.1416 x 5.2 x 5.2 x 4.95) / 4 = 105cc

Re arranging for stroke, volume (0.104L) in liters to get mm

(4 x 0.104) / (3.1416 x 5.2 x 5.2) = 48.97mm or 49mm

So 49mm stroke and 52mm bore gives you 104cc

And a 48.5mm stroke gives you 103cc

Gee that sounds like a lot of hard work.

Bore squared x.7854 x stroke/1000=cc

[speedpro]

Are there any KT pistons that go more than 52? Thought they were clamped on size bar tiny clearance versions

They go out to 53mm plus the local shop has other pistons I've seen up to 53.75, there may be others. The genuine Yamaha and the KSI brand pistons are available in 51.9?mm to 53mm in .05mm steps.

Turns out the kart guys change their KT100 pistons every 5-6 hours, the fast guys do anyway. There are other brand pistons they have as well including some lovely ones with Dykes rings and coated skirts.

With the small increments you just hone the cylinder and fit the next size up piston. Generally you fit the next size up again ring keeping an eye on the end gap. So a 52.15 piston would be installed with a 52.2 ring.

[husaberg]

Strike do these are the J pistons too BTW. Not the ugly "s" ones.
they seem to go to at least 53.45mm
http://www.strikeproducts.com.au/pistons.asp
PJ002 - Piston KT100J Big
http://www.strikeproducts.com.au/UserFiles/Image/PPJ001.jpg
To suit Yamaha KT100J for speedway racing applications.

Sizes are made to order for a range between Æ52.0 and Æ53.0

Ring to suit is p/n PRS001

[Bert]

They go out to 53mm plus the local shop has other pistons I've seen up to 53.75, there may be others. The genuine Yamaha and the KSI brand pistons are available in 51.9?mm to 53mm in .05mm steps.
I have some vague recollection (talking to kiwikarts years ago) that they make them out to 56mm or something to make a 125cc kt's... might be worth asking about.


Turns out the kart guys change their KT100 pistons every 5-6 hours, the fast guys do anyway. There are other brand pistons they have as well including some lovely ones with Dykes rings and coated skirts.
yip that were I sourced a few of mine when I was a poor student / poor worker / I'm still poor but not using KTs anymore... Dyke ringed piston are/were generally European; HPV, Komet & Corsair.. never really saw many of them here in NZ. that remind's me: http://www.kartsandparts.ca/store/home.php?cat=37 some interesting options worth considering.


With the small increments you just hone the cylinder and fit the next size up piston. Generally you fit the next size up again ring keeping an eye on the end gap. So a 52.15 piston would be installed with a 52.2 ring.
That real important for best performance; and also really important to check and adjust the end gap of the oversize ring; they tend to make a little bit of a mess of your exhaust port when they heat up and pop out :facepalm:

[F5 Dave]

Strike do these are the J pistons too BTW. Not the ugly "s" ones.
they seem to go to at least 53.45mm
http://www.strikeproducts.com.au/pistons.asp
PJ002 - Piston KT100J Big
http://www.strikeproducts.com.au/UserFiles/Image/PPJ001.jpg
To suit Yamaha KT100J for speedway racing applications.

Sizes are made to order for a range between Æ52.0 and Æ53.0

Ring to suit is p/n PRS001
That picture you have seems to have the pin about 4" from the crown.

[husaberg]

That picture you have seems to have the pin about 4" from the crown.

Its a picture Dave, from the strike page. The pistons they sell are to J and s spec maybe the pics are round the wrongway?FIIC
But a j piston is a j piston.(What ever the pic shows) An s piston and is a different beast. but yes it looks more j than s.
you could use them in your Non Honda Honda so it would have even less Yamaha parts:innocent:

What the fuck shit how did i do that an s piston is the STD model kart isn't it . so f'ed that one up Good and proper whoops.

Start again whoops an a f-ing big way

this is the beast you want.

Looks like they will do custom to suit.
http://www.strikeproducts.com.au/UserFiles/Image/PPS001.jpg
PS003 - Piston KT100S STD 53.75 and above


To suit Yamaha KT100S and ARC SPEC100 for AIDKA and Speedway racing applications

Sizes are made to order for a range between Æ53.75 and Æ55.0

Ring to suit is p/n PRS002

PS004 - Piston KT100S Special


For custom applications for AIDKA and Speedway racing applications

Custom options include:


High Ring

Rotated Anti Rotation Pin for reeds and rotaries

Dykes rings


Sizes are made to order

Rings to suit are dependant on application

PSS001 - Piston KT100S Smooth Finish


Smooth piston skirt finish

To suit Yamaha KT100S and ARC SPEC100 for AKA racing applications

Size increments 0.05mm between Æ52.0 and Æ52.75 then 0.01 increments above Æ52.75mm

Ring to suit is p/n PRS001

Drugs don't do them kids

[F5 Dave]

Heck I dunno, all this kart stuff is greek to me, but that 2nd picture looks more to proportion. Anyway, what have you got against Dykes & their rings?

[husaberg]

Heck I dunno, all this kart stuff is greek to me, but that 2nd picture looks more to proportion. Anyway, what have you got against Dykes & their rings?

I have nothing against the dykes more power to them. ESP topless on bikes.

But the thing is wob hates them and he's know more about them than me. According to him they supposedly rob a lot of power with friction which is a pain. Mainly cause all the pistons i found to suit Vanessa were lezbo equipped.:whistle:

[speedpro]

I put a set of Moriwaki 2 ring pistons in my old Z1. The compression ring was a dykes type. The difference was amazing. The pistons practically fell into the cylinders and the whole motor could be turned with no effort at all. When it was running however it was all good.
Personally I don't think Dykes type rings "increase" friction. It made a lot more power as well but that could have been helped by the huge valves or maybe the Moriwaki F1 cams or the new Keihin smoothbores.

[husaberg]

I put a set of Moriwaki 2 ring pistons in my old Z1. The compression ring was a dykes type. The difference was amazing. The pistons practically fell into the cylinders and the whole motor could be turned with no effort at all. When it was running however it was all good.
Personally I don't think Dykes type rings "increase" friction. It made a lot more power as well but that could have been helped by the huge valves or maybe the Moriwaki F1 cams or the new Keihin smoothbores.

Yeah like i said no practical experience with them but i tried to include some in my build as they were easily available in sizes to suit but Wob wouldn't have a bar of them and as the best MX and GP bikes built since the 80's seem to have avoided them as well there must be a reason i guess.:scratch:

This is part of what Wob said in an email.

The IAME kart pistons use L dykes rings to stop flutter ar 20,000 but have huge bore tension and wear out bores in no time, not an issue in the karts where they get rebuilt every 5 minutes.




As they Dykes style rings rely almost solely of gas pressure to seal i surmise they would only increase the friction load (against a conventional style) whilst under operation.
As Vanessa will be a 14000-15000 RPM engine the Dykes was a no gainer for my build.
TZ just posted this in the autopsy thread i guess instead of here.
A good read on piston rings:- http://americanmusclecarsaustralia.com/forum/viewthread.php?tid=2627
But it seems to back up the bore wear theory anyway.
Some guys in the blown fuel classes use stainless steel Dykes rings. The L-shaped Dykes or headland ring typically has a 1/16-inch face with an 0.017- or 0.031-inch step in the back of it, offering gas pressurization without the need for gas ports. Dykes rings need a special piston, are hard to seat, and accelerate cylinder-bore wear, so they're preferred for only very specialized applications.

[husaberg]

Anyone know the weight of a mb100 engine?

[speedpro]

yes .

[husaberg]

yes .


Thanks,So how are you going with the book?

[F5 Dave]

I'm still real confused by the stator you used. All I see are stators that get bolted on like this to the engine case, there is no backing plate like you have.

http://www.ebay.com/itm/CRF250X-2004-2010-NEW-OEM-STATOR-GENERATOR-IGNITION-MAGNETO-CRF-250X-CRF250-/110846465786?hash=item19cef6d6fa&item=110846465786&pt=Motorcycles_Parts_Accessories&vxp=mtr

250X & 250R appear much the same.

even the flywheels are reversed & look similar but different.
http://www.ebay.com/itm/2006-Honda-CRF250X-Flywheel-Fly-Wheel-06-CRF-250-X-250X-/130658265608?hash=item1e6bd6ea08&item=130658265608&pt=Motorcycles_Parts_Accessories&vxp=mtr


edit. . . .ahh, it must be for a CR, 2 stroke MX, not CRF!

[F5 Dave]

Oops, just bought a CR250 '02 stator & f/w. 8 pole & same as 125. From what I can see, 03 is a 4 pole for the 125 & there is a dif for the 00, 01s to the 02 onwards, but not sure what it is.

One could buy a 50W upgrade kit & you can get pirate ones quite cheaply but have to buy a flywheel so best to find one seller.

But this will drive my pump ok & then cope with an Ignitech & soil carb. . .one day.

[speedpro]

New shiny bits, which when you zoom in look really rough. More coming this weekend, plus I've ordered a new stroker crank and a 65mm big bore kit with forged piston for my scooter. Better figure out a way of paying for it all now.

[koba]

New shiny bits, which when you zoom in look really rough. More coming this weekend, plus I've ordered a new stroker crank and a 65mm big bore kit with forged piston for my scooter. Better figure out a way of paying for it all now.

In the photo I see 'KIWI' so it must be made in NZ :facepalm:

And I see 'Quality' so it must be of exceptionally good quality :shifty:

[husaberg]

In the photo I see 'KIWI' so it must be made in NZ :facepalm:

And I see 'Quality' so it must be of exceptionally good quality :shifty:

I see in the background what looks to be the miss'es Kitchen bench top.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=262240&stc=1&thumb=1&d=1334732221
So he is living dangerously, or she' out and hes cooking up some special.

Great place incidentally to assemble engines it should be tidy, and freezer(bearing cooler) , Jug and parts washer (Dishwasher) and oven (Case preheat-er) Rags (tea towels) but make sure you put the plug in the sink:shutup:

[speedpro]

With help from TZ350 I now have the crank back together. Him and I have been whacking it with hammers and prying it with a big crowbar and it still isn't as good as when we first pressed it together :doh:
I've got a few more to do so it's good practice.
Unfortunately I have more pressing matters to deal with this weekend - putting my scooter back together. All the parts have arrived so it'll now be a bit over 200cc.

[Yow Ling]

With help from TZ350 I now have the crank back together. Him and I have been whacking it with hammers and prying it with a big crowbar and it still isn't as good as when we first pressed it together :doh:
I've got a few more to do so it's good practice.
Unfortunately I have more pressing matters to deal with this weekend - putting my scooter back together. All the parts have arrived so it'll now be a bit over 200cc.

Get a bigger hammer, I dont find practice makes perfect, they all different, you adjust one one way and they move in a diferent plane, others just take one hit, some are just plain rooted, helps if when you press it up it not too on the piss, I did one for a friend and peeled the inside of his crankweb, that wasnt my proudest moment. This weekend Im going to have a stab at boring the crankwebs to go from a 19mm pin to 22mm Ill practice on a scrap crank this is at the uncomfortable end of things for me.

200cc scooter will be cool, they eligible for buckets eh , you know they just a scooter

[crazy man]

With help from TZ350 I now have the crank back together. Him and I have been whacking it with hammers and prying it with a big crowbar and it still isn't as good as when we first pressed it together :doh:
I've got a few more to do so it's good practice.
Unfortunately I have more pressing matters to deal with this weekend - putting my scooter back together. All the parts have arrived so it'll now be a bit over 200cc.dad made a jig up for pressing cranks together he did not have to do anything to it after it was so good

[speedpro]

First off it was only .1mm runout, a quick whack with the hammer sorted that out. I'm surprised how flexible it is. It takes no effort at all with the crowbar to spread the crank webs and a tap with the hammer to close them back up.

When I say sorted I mean it is now .3mm and just changes from being out one way to being out another way, grrrrrr.

[husaberg]

First off it was only .1mm runout, a quick whack with the hammer sorted that out. I'm surprised how flexible it is. It takes no effort at all with the crowbar to spread the crank webs and a tap with the hammer to close them back up.

When I say sorted I mean it is now .3mm and just changes from being out one way to being out another way, grrrrrr.

it's so satisfying that something as precise as a well trued crankshaft can be achieved with what is a blunt unrefined instrument. (The Hammer)

[F5 Dave]

I did one for a friend and peeled the inside of his crankweb, that wasnt my proudest moment. . .
That's what happened to my RGV150 crank last time (I paid someone to do it), had to get it redone & welded so it would stay put, but the end of the road so when the crank lost plating on SE it was throw away sort of stuff.

[speedpro]

I'm probably going to get a good design pipe for a kart track MB100. 192deg exhaust port, 127deg transfers, 12,000rpm. Currently thinking of getting 3 lazer cut or more if someone else wants one. Don't know the price yet but of course it will vary with quantity. I'm going to supply all the bits like a machined mounting flange and machined stinger nozzles as well. I don't mind making them complete fitted to the bike but that is a lot of work so could get expensive or could just roll them up and let the purchaser fit them together. .8mm mild steel. My current mounting flange is fabricated from 1.? mild steel and is nice and light and a real good fit but I'm thinking a machined one from alloy might be as good and flasher. PM me expressions of interest.

[husaberg]

Have you looking seriously into a MB100 Disk conversion Mike, perhaps with a sleeved NSR top end?