the compression is good,around 110,i droped oil in the hole thinking it was fuel washed,it ditn help either,the timing is only other thing i can thi8nk of ,it ran good the other day,and went down hill from there,30 mins after it ran good,i ran it again,it stumbled pissed and poped,at any throttle speed,idle was ok,now it wont even start,no i didnt check exhast valve,even it thats to tight,it should still run,just backfire alot,<i tink anyway>i take that cover off,i c a bolt <17 mill> to turn the flywheel,for the timing,i dont c any key though,is it behind the 3star plate next to the bolt,

 

That compression is good enough, it shows the valves cant be out of adjustment too far.
The ignition timing is probably good, its a long shot, for the key to shear and have the flywheel advance.
Youre back to carb related. When you spin over the motor...can you feel air rush thru the air snorkle? You have the air box lid on, and have a clean air filter? When you open the drain on the bottom of the carb, does gas come out the tube?
When you move the throttle...does the linkage on the carb move?