Recently rebuilt my sportsman 500 and i cant get it to run. I think the timing might be the issue but i cant seem to get it just right. The pin in supposed to be in line with the stroke but it is either a lil to one side or a lil to the other side if i move the chain on the sprocket. Will the timing being about half a tooth out cause it not to run and what might be causing this.

 

Could be timing or some other electrical or mechanical problem,but one tooth off one way or the other on timing shouldn't stop it from at least running.Make sure the lower crank sprocket hasn't split the woodfuff key,plus eliminate any carb or fuel problem.