Quote Originally Posted by Damien_63
So backfiring is a good indication that the timing is off?

Yep. The valves are supposed to be closed on the piston being fired (when the engine is in time) but when you are out of time, the spark is hitting that cylinder when one or both of the valves are open to some degree, and the exposion escapes the cylinder. If the intake valve is open, it backfires through the carb. If the exhaust valve is open, it backfires through the exhaust.


Don