stang007

I leakdown tested it after building it earlier this week and it held the full 6psi for 6 minutes and the gas I'm using is fresh as well. I didn't check my squish...will have to do that, just assumed since it worked before that it would work now since all the parts are the same except for the domes and I wouldnt be going through this.will try turning the timing down to +3 and go for a ride and see what happens.

I'm having a problem with the plug backing out of my left cylinder only...it's done it 3 times now and happens after about 20-40 minutes of riding. I run my timing at +7, have 20 cc domes, and run straight 110 octane at 32:1. Ive run this same setup for 3 dune trips now and 2 seasons and never had an issue, but took it out the first time this year and it happened at the end of my first ride. At that time, I also noticed some extra oil build up on the right exhaust pipe and so I took the motor out and split the cases to replace the crank seal...that problem solved. I leakdown tested it and it held all 6psi for the 6 minutes. When putting it back together, I bought a fresh 4 mil cheetah cylinder and pistons as well as 19 cc domes this time. I also turned the timing down to +5 degrees. I've been breaking it in the last couple of days and tonight it popped out of the cylinder twice...again only on the left side, again after about 20-40 minutes of vigorous riding. The bike is running super strong and I'd say the jetting is pretty much spot on by looking at the plugs and just listening to the bike through different phases of riding it.. I can't hear any detonation whatsoever. Both carbs are adjusted identically and so I am baffled. I know people say that plugs typically back out because of detonation or preignition or even running lean...but on one side only? Oh, and yes I am tightening them correctly. Any suggestions or tips would be greatly appreciated...