Major Power Loss????

Message

toothandnail · #11 Post by **toothandnail** » Wed Aug 20, 2008 1:50 pm

Yes the throttle was held wide open and I let the motor crank 4-5 times.

The 50 psi limit would explain the hard starting I encountered at the race.

Based on the tests I have done and everything you all have said I think my rings are bad or I have a leaky valve. I will be pulling the motor tonight so I will let you know as soon as I find out. Thanks!

thedeatons · #12 Post by **thedeatons** » Wed Aug 20, 2008 4:07 pm

I have encountered 50psi when my cam timing was off, but it was way off for that to happen. That was during my first attempt at timing the cams.

Chances are since you went from good power to low compression/no power, you lunched the rings or a valve... Sorry to hear that.

toothandnail · #13 Post by **toothandnail** » Fri Aug 22, 2008 6:56 pm

found the problem, cams are shot , again, original ones lasted through several yrs of racing , new ones , 4 races.
Any other options for cams yet?? I don't feel like pulling the motor every couple months. Can't get hold of timbo, Brads out of town for a while. I was hoping to get some parts ordered today(Fri) ,so I can put together early next week.

Man ,I sure miss the good old days of rebuilding a 2 stroke.

2000ex · #14 Post by **2000ex** » Fri Aug 22, 2008 8:03 pm

It is a crapshoot it seems with the cams. The bike I just picked up maybe has 10 hours on it and the crank was shot and the exhaust cam was round and buckets junk. Is there ANY way that we can determine which ones are good other than the FX cams or running a rockwell test on them before? Which ones seem to be the bad ones, the 4 hole ones or some of the later 12 hole variety?

Happyboy · #15 Post by **Happyboy** » Fri Aug 22, 2008 8:17 pm

did you replace the cams and buckets at the same time? what were your clearances?

toothandnail · #16 Post by **toothandnail** » Fri Aug 22, 2008 11:27 pm

New cams and buckets , shimed to the loose side of spec , because of new valves , seats . maybe they wore in more than they should have, that's always a possibility, however it was running fine until this last race, although it might have started in our last 2 runs in the rodeo(which we SMOKED everybody else)
It seems that once they start to wear they go real fast

ozarkdaler · #17 Post by **ozarkdaler** » Sat Aug 23, 2008 3:51 am

I know this is off subject but are you coming down to Ava for a TT race or will you have another one in Versailles?