Vintage Road Racing Association

wheel building on Good Friday

the good and the bad, 1st the good, I got the bike done for shannonville track day yesterday. everything working as it should. brakes and suspension set-up right, super light and handled perfect. 2nd the bad,
after running the bike 2-3 heat cycles at low revs, i took the bike out on the track, 5-6 laps keeping the revs down between 6-8 grand the bike ran smooth, 2nd session more laps and more revs, staying under 10 grand. bike ran great, 3rd session, more laps and more revs. this motor should make power to 12, and everything seemed right, then 6th lap, opening it full down start/finish straight going into turn 1, poof
black smoke out of the left pipe and power dropped off. oil pushed up through the breather into the catch.
broken ring? scored sleave? today i'll do compression check and leak test. oh well that's racing

Nice bike! Too bad about the troubles.

Very Nice. Those pictures really make me wish I never sold My cb350 project, and would have stuck with it. I had a similar vision for mine, seeing yours all finished makes me really want another one...

Dan Dubeau wrote:Very Nice. Those pictures really make me wish I never sold My cb350 project, and would have stuck with it. I had a similar vision for mine, seeing yours all finished makes me really want another one...

If you want one that bad I have one collecting dust in my garage that I'm willing to sell. Full fairing so no belly pan needed. PM me if you are interested.

G

please send me some photos of your dust collector and a price. May be interested. I have one now that will be a big project to rebuild completely. May be more sensible to buy one mostly built and sell off this one to someone more inclined to finish it in a lifetime. I have too many other projects on the go.
send to bcameron002 AT gmail DOT com
Thanks

aly393 wrote:.... this motor should make power to 12, and everything seemed right, then 6th lap, opening it full down start/finish straight going into turn 1, poof ...

Sorry to hear the bad news Alan, whoever told you it would make power to 12 are no doubt the folks that sold you the bits you will be replacing, a shame. Anything after 9500-10000 are and will be extremely expensive rpm's as you are discovering, and really not enough more power if any to risk the motor. P1 cb350's bullet proof, p2 build cb350's, better have the disposable income like the big boys, BUT, nothing sweeter than a strong p2 350 to shock the non-believers in the capabilities of this fine wee bike.

Cheers,
Mike

Barber Bound .... just need the right bike

hey Allan...
any news yet on the motor ?

Scott

the good and the bad part2, engine came apart, the top is good , no valve damage, the left poof , was that the left carb ran really lean, set up wrong ? blockage ? i have to look into it. but the good news is, I only have a punched hole in the piston! there is a bit of alloy smear at the top of the sleeve but, it can be howned. it will be ready for Quinte, I HOPE

That sucks. Hope you get it together and find the source of the problem.

TimV

crap....that really sucks

what about the fuel octane vs. compression level issse we talked about ? Maybe it just detonated itself to that point?

Scott

I talked with Buff Harsh and Gord B about it and they both said you can get away with running 93 , I think that is all I ran in my 500 , I'm going to have a close look at my carbs today
Allan

FYI, I run straight race gas in mine...but that may not be the reason either.

I dunno Allan..
Harry runs about 11:1 compression in the CR750's and they run only VP C12 leaded (about 110 Octane?)...93 octane with 11:1 to me doesn't seem to provide much of safety cushion for that set-up..could be wrong?.. I blend 100 octane with Shell 91(50/50) with stock compression ..probably overkill for an air cooled engine but on a wickedly hot day it's a small bit of reassurance that I wont be Pinging it ?

Scott

It's like the MOB says....It might be OK ...but why take chances ?