Anthony Marceau

And it is not running lean! I tried shooting gas directly into the intake with a spray bottle while giving throttle and it just dies..

Done, done and done! I just rebuilt the carb yesterday with brand new parts.. the carb is clean! I noticed it's spitting gas mist from the carburetor as if the intake valve wasn't closing all the way! Valve clearances seem good and timing too!

Hi everyone! I have a 1986 yamaha moto4 200 that's been sitting for a while! Cleaned the carb, replaced engine oil, put fresh gas in it. Got it running and went for a ride! It was running great just a little backfire once in a while! I barely made it home on the way back and now the bike won't run at all since then! It will start if I give a little bit of throttle but dies instantly as soon as I let go off the throttle! And even if I try to rev it up it'll sound like its not getting enough gas.. it revs up a couple hundred rpm's and backfires through the carb.. it almost sounds as if I was trying to take off from zero in 5th gear! Nothing is seized though! I dissasembled the head and the piston and cylinder are fine! Rebuilt the carb, replaced the ignition source coil.. I don't know what to do anymore.. compression test shows 90 psi Specs are 128 psi but i'm not sure if I trust my compression tester.. any ideas? Thanks!!