Backfire thru muffler?

During compression braking engine wil backfire thru the muffler.
I have a small leak where my header and temporary muffler join. Is it possible this is creating the problem by allowing fresh air up the exhaust which ignites the rich air fuel mixture as it comes out of the exhaust valves? (I do know the carbs are too rich for the motor)
I once had mistuned carbs blow a muffler apart and while this is not a concern, I do not need any extra atttention from the local gendarmes.

Ralph, Is it possible you had a second helping of baked beans, may explain the popping you hear.

Bruce

its a combo of rich mix/low back pressure (i think).

Check the carb to manifold gasket. Make sure the nuts are snugged up, mine had a way of working loose until I put some loctite on them.
ed

Thanks guys. You have validated my theory and of course the reason I have an exhaust leak is cause I have jerry rigged an old muffler onto my new ceramic header while waiting for parts from S&S and since it has been unseasonably warm here I want to drive it.

Ralph,

The back fire is usually caused by oxygen rich air being introduced into a HOT fuel vapor rich environment. It's most likely caused by your gasket leak. You shouldn't have any exhaust leaks anyway, bad for you, your image, the car, AND the exhaust valves. Come on, it's a custom built "performance" car, spend the $1.15 and grab a gasket. Minimun, squeeze in some sealant and tighten the nuts.

If it were a leak upstream at the carb to manifold gasket you'd have a lean condition due to the increased air entering before the head/combustion chamber(s) and you would most likely hear a whistle or hissing sound.

Luck,

TC

Ralph,
I must have missed it somewhere in this thread. Which carbs are you running?

If they are dellorto's, clean your air correction jets. (the (long) ones you can see as you look down at the top of the carb.

Greg B

(right drclock?)