Backfire

[DolceCJ]

AMC360, backfires out the right header sometimes under acceleration. Possible causes?

:lo1l:

[DolceCJ]

This seems more noticable when the engine is warm. Would a lean fuel mixture cause this? iF yes how do I change that?

[jeepsr4ever]

I would look at timing and check to see if the carb is flooding her out.

[tufcj]

Lean condition would cause a backfire out the carb. A pop out the exhaust would be a rich fuel mixture, retarded timing, or a leaky gasket at the head and/or collector.

Bob
tufcj

[northplainsdrifter]

I had a flat cam lobe once and it would pop out one side, more when I let off on the throttle.

[DolceCJ]

It doesn't backfire out the header during deceleration, and not during idle or easy driving, just during acceleration.

The timing is 6-8 BTDC. Manual transmission. Guess the rich fuel misture would be easiest to try to correct. How do I do that? Some plugs are black (also a sign of rich fuel mixture?)

[ironman_gq]

I had one with a really stretched timing chain that would pop out both ends under acceleration. Scared the $hit outa me one night when she popped out the carb and I could see the light all around the hood and the road.