This post was originally in another thread, but It needs to have it's own topic. This post was made originally by bill2099. Thank you to bill2099 for the information.


here's how to adjust the valves this came from a offical honda manual for the 50-110cc engines.

1. remove valve caps to access tappets, remove left side flywheel access covers, theirs 2 of them one on top with slot one on the side with slot.
2. rotate the flywheel (counterclockwise) until the "T" mark on the flywheel aligned with the index mark on the engine casting, this should be center of the top access hole. this is the top dead center (TDC) when the piston is at top of its stroke either at the compression or exhaust
if the rocker arms won't rock gently, then you are at the end of the exhaust stoke and both valves will be open, so rotate the engine a futher 360 deg until the engine is at (TDC) at the end of the compression stroke, now both rockers should move slighty
3. insert a .002 in (05mm) feeler gauge between the tappet adjusting screw and valve
if it too tight or too loose then adjust the gap by releasing the tappet adjuster lock nut by 1/4 -1/2 turn, turning the adjuster, retighting the lock nut and checking the gap again, you may need to do this several times to get it right as the gap changes while you tighten the locknut
4. repeat this for the other tappet
5. refit the tappet covers and the stator access covers

note: the top access hole is to check timing marks, the center access hole is to be use with a scocket to be able to rotate the engine,

this may look a little intimidating but its really reather simple

 

2 thousandths .!!!! dang that is tight . i had no idea they ran that tight.

 

Little bump