Well I knew the valve was sucked into the head, and I figured it was an 87 moto 4 it has served me well for 20 years, might as well check the cylinder and piston, cylinder was out of specs, needed to be bored over, necessitating the piston and rings, could have reused the old timing chain but it was 20 so why not spend 14.00 to replace it too and new gaskets and labor for the overbore and valve job came to 198.00 plus my time tearing everything apart and rebuilding the motor.

I also changed the carb to one from a 2006 raptor 80cc because mine was pretty well worn out and they had one at my local dealer for 75.00 that had like 10 miles on it.

 

I doubt there is anything actually internally wrong with the engine. Adjusting valves is just a regular part of maintenance. It's normal for tolerances to slowly drift as engine parts wear over time. Not saying that there isn't the possiblility of the valves actually being worn down, but 95% of the time they just need adjusted.

 

hello
well thanks for every thing guys!

 

actually it is very common as these little 80cc engines get older the intake valve gets beat to a pulp(it is too soft of a metal) and sucks up into the head causing it to be stuck