i have early 90's yamaha warrior 350
not sure the exact year the engine started ticking badly, sure i a bent a valve i just kept riding. caz the family just got to the atv park and i wasn't going to let a blown motor stop their fun. i got around tonite to pulling the valve covers and found lash nut on one of the rocker arms missing,or hiding. not the first owner of this quad but the first time ive opened it's 350 warrior engine i think i have a theory. tell me if its sounds right.
with a magnet and flash light i could not find a nut in the valve head, to the best i can see on the net theirs no way for that nut to find a passage big enough to make it to the bottom of the motor. the lash adjustment screw was backing itself out of the rocker arm 1/4" ( i road most of the day like that) the reason for the noise. when i screwed it back down it got tight right at the spot it would have been set, like someone put lock tight on it or bent threads in a effort to secure it. im beginning to believe there was no nut. i dont want to pull this thing apart looking for a phantom nut. can anyone confirm that the return passaging are too small for the lash nut to make it to the bottom of the engine. motor sounds great now but damn wheres that nut?