Question: a friend rode his bike without antifreeze for quite awhile. I went through valves and carb to get it running right. as it warms up it starts snap crackling and popping. After cleaning carb and trying to get fuel mixture right. the thing isn't sparking at the plug. Mechanically amazingly the engine seems ok. Would the heat of the engine destroy the stator? It looks bad actually. so hoping someone has similar experience.