Hey folks,
Got my 90 runnin, turns out that the timing was off (it would try to fire while the intake valve was still open). How this happened I have no idea, because all the screws that held the magneto and components were tight. Could the cam chain have slipped? I tightened it according to the book I have. How do ya'll tighten yours? I thought maybe that the advance unit may have stuck so I WD-40'd it and seemed to work a little smoother. Any idea how this could have happened? THanks!