Quote:
Originally Posted by Blue Thunder
Sure. Without getting too overly technical a 4 stroke engine does just that. Intake, compression, power, exhaust. When the piston was coming up for the compression stroke, it wasn't really compressing much, hence the 45 psi of compression referenced earlier in this thread. The spark plug fires within a few degrees of top dead center. When that fuel/air mixture ignited it would blast right by that huge crack in the intake valve and backfire out through the throttle body. I'm assuming the valve pictured is the intake. If it's the exhaust valve the same thing would happen but the backfire would go out the exhaust port...
BT
|
Thanks for the explanation.
What has me wondering is the inconsistancy of the issue as reported in the first post. It seems to me that a valve like that would give a more consistant symptom.