Will I get my 100 ready in time for Taupo?

[F5 Dave]

Well I've fitted the pipe & put it back together. I made a venturi stinger insert to replace the RS125 one as it's (obviously) suited for a 125 being 23mm, but it's pretty cool as I can machine up any 25mm tube 25mm long & swap it in to test. This one is bored 18mm & tapered with a 9deg cut to 1/2 way along & a 40deg cut on the baffle cone side with a 8mm section at 18mm. I have a formula somewhere but this was just cut as an experiment being a couple of mm smaller than typical for a 100. Looks nice too. Must be worth a couple of horsepower just in trickness.

Having too big a stinger bleed can actually lose some reasonable power.

So off to the dyno. Seemed like a waste as the day disappeared. Maybe I should be out on the road bike, or the trials bike. Weather was sunny & wind calming down. Oh well.

So either way the PC is playing up, she's an old girl. Like there's a stuck key. Finally I get a run. It towers over the old WC barrel, but that is hardly hard. This run had the RS stinger 23mm tube (too big but wanted to see the diff when putting in my venturi one). Touched 20hp, not bad for a first run, bit above 12k & over sharply thereafter so conservative. Had a bit of a dip before peak power, but this was the first run with whatever jet & ignition timing where it landed. next run was up a couple of jet sizes as it was pretty small. I was heading for the van for tool & there was a crash, the weather set in with a storm. Hail etc. The BANG, the PC goes pop. Hmm, that's not good. ctt breaker. phew. But the PC won't start, so it's gone pop. Power surge or just age? Hard to say, but that's the day done. Retd the ign & with jet size bigger to be safe. Did put the restrictor venturi in as it should be better. Not sure if I'll be able to run it up before next test day, but at least it goes & doesn't seem to drool oil.

Hoorah.

[F5 Dave]

Well another trip & the PC still isn't working so I'm scrounging PCs from work now. Gee who thought 2 stroke tuning would involve so much computer work?

Well I have largely got the bike raceworthy. I've pulled the front end off the other bike as I want to run the RS wheel & that front end had the lock stops broken off the triple clamps. So I drilled & tapped some M10 holes & fit munty allen bolts with nuts. The headbrg was mullered so I need to replace that. Hopefully I can get one in time.

[F5 Dave]

Finally got a going PC, but haven't been able to get to the dyno for the Snow, sheesh I almost didn't get to my home yesterday. Did battle my way into the garage & replaced the head bearings & drained the forks & cut down some springs/spacers etc. Have to put it all back together so it means dyno tonight unlikely. Maybe won't get to test run before weekend. Having said that - who knows what this crazy weather will be doing this weekend?

[koba]

Finally got a going PC, but haven't been able to get to the dyno for the Snow, sheesh I almost didn't get to my home yesterday. Did battle my way into the garage & replaced the head bearings & drained the forks & cut down some springs/spacers etc. Have to put it all back together so it means dyno tonight unlikely. Maybe won't get to test run before weekend. Having said that - who knows what this crazy weather will be doing this weekend?

I imagine your hill would have been quite frightening...

[F5 Dave]

no problem at all until the last few corners & then it all changed. The driveway was the worst though.

Well forks all back together, ready to rock. No do I get to the dyno before race day? There is that dip before peak that is not going to be that fun, it would be nice to try tune it out if possible. 'Course American Dad is on telly & it will be cold. . .

[F5 Dave]

Ahh screw it I sed. So tried some things on the dyno, some successful, some not so. Overall power is up & the dip is considerably reduced so it should be easier to ride. But it showed this bike likes an ignition curve something different to the RS one. Rtd it likes to rev on, advanced it fills in the dip & peak is earlier & a tickle more. oddly the lower part of the power curve (9000) is less when advanced.

My venturi insert was worth some power. . . . But in the wrong way. more sizes to try I think.

[Buckets4Me]

But it showed this bike likes an ignition curve something different to the RS one. Rtd it likes to rev on, advanced it fills in the dip & peak is earlier & a tickle more. oddly the lower part of the power curve (9000) is less when advanced.

sounds like you need a programable ignition
go get out the cheque book

[F5 Dave]

No funds in bank for that. My 500huny 2 stroke has gobbled them (prog ign was the cheap part for that). Just had the new seat & steering damper turn up for the dirtbike & have to pay for suspension revalve on it. My cup runnith under Oh well I'll just have to live with it & ride the sucker.

Next on priority list is the carb was dripping from the overflow so that needs to be fixed & the steering lockstops are too close in (I copied the previous attempts assuming they were in the right place. They are now strong, but maybe another grind may get enough movement). Then it's race meet on sunday & see if it actually goes ok on the track (on its aged slicks whilst snow still lines the track (no kidding).

[F5 Dave]

Well that was the shakedown run. And nothing fell off. Except the swingarm nut Even the tyres weren't too bad, although they weren't the best either. I've made a list of things to get onto but then locked the bike away, the 500 is the next on the list . . . after the dirtbike.

Ran ok but the dip before power isn't the easiest to cope with & slows the bike a bit.

Hey at least it runs! 15 years on.

[F5 Dave]

Well the 100 has done its 2nd race meet & now this thread is topical as TAUPO RACE IS ON AGAIN FOR NOV 11!!

So maybe the thread should be "Will the bike still be ready for Taupo?"

In 3 weeks it has a Kaitoke race meet & then the week after Battle of the buckets in Chch.

Still 'only' 20hp & with a dip before peak power. I need to make another pipe rather than the 125 pipe that was to get it going. Money & time aren't on my side. My experiments with venturi stinger weren't successful so I will try other dimensions. Reeds are still steel so that can change.

Bike runs ok but doesn't pull up into the power very well. Once it's there its nice. Well until it dips in power & then peaks up again. If the change falls into the dip it hesitates.

Still it has got me going & up a few places in the A grade. A new pipe should make it way ore rideable & I have two designs to progress, just the best way forward I have to work out. Buy some of my trademe shit so I have some coin.

I need to start on the new cases as these ones leak, but I need some money to buy a different carb to fit up, this RGV one isn't the way forward I have decided, want to get away from the over down-draft.

[hmurphy]

That 100 of yours looks sweet on track. I like the colours and it's FAST. It will be great when you have all the finishing touches on it. I still haven't had a ride on your 50, and now I want a go on your 100 too haha. Trust me Dave?

[Buckets4Me]

pics or it didn't happen

and congrats between you nad Mike G there must be 30 years of bucket building to get 2 bikes finshed (1 bike 1 engine)

but thats half the fun
TZ is still going and I heard talk of 35 h/p at the rear now (he was only after 25 when he started)

[husaberg]

.

I need to start on the new cases as these ones leak, but I need some money to buy a different carb to fit up, this RGV one isn't the way forward I have decided, want to get away from the over down-draft.

Have you got any pics of the engine I for one would like to see what it looks like esp the barrel head and Crankcase induction.

[James Deuce]

Do you need a computer? I have one if you want one.

[F5 Dave]

Pic in page 1 but I won't do it again like that. - it was a rubbish implementation & just looking it again last night, its so wrong. That being said it gives me scope for improvement.

I cut some reeds out last night. I only had enough sheet to do one side properly & the other is from an old reed which is too thin so I made a siamese wing to boost it. Just looking on the net for more cf sheet just found a scooter site Treatland.tv.

Machined a couple more venturi sections to trial.

Still need a change in pipe & also to make some new cases as these ones leak & will be lowing power/affecting carburetion.