Bonneville America Forums Forums Technical Forums Performance Mods whats that popping

I removed the AI, rejetted and removed the airbox. Now when I decelerate I get more popping in the exhaust than before the mods. Is this normal?

You should get some but not much. It should sort of rumble a little. If it is doing too much you may have an exhaust leak or you need to adjust the pilot screws ,if that doesn't do it you may need a larger pilot jet.

I get a bit more popping than I think I should as well. You mentioned the exhaust leak possiblity. How do you check for that or how do you check the seal between the pipes and headers? Dish soap mix?

Just use high temp silicone where the pipe meet the headers, Smear some on the inside of the pipes, I go the depth of the slits with a thin coat. At the heads just make sure the nuts are tight that hold the headers on and look for any blackening from exhaust leaking. Some guys have had the headers work loose. Depending how many miles you have you may want to consider new head to header gaskets if you think they are leaking there. I tend to think you wouldn't need those unless you have quite a few miles and it's been leaking.

My annoying pop was indeed the left manifold to head connection, a new gasket and high temp silicone did the trick.

Initially on my 03, I had to retorque the manifold nuts a few times before they finally stayed torqued. I check them now at every oil change and they're ok.

Thanks Dog. It took me a while but have sealed the TORs to the header and will do the mixture next using your recommendations of pulling the left plug and getting a smooth idle on the right, etc.

You will have to turn up the idle some to adjust once both sides are adjusted then turn the idle back down to where you want it.

Don't forget to seal the crossover pipe between the headers.

Pipes are sealed and adjusted the mixture 3 turns out. No sharp pops any more that I notice. More of a decel rumble. Likely need to play with the mixture more as I do not get the rumble when I back off the accel slowly. The only other thing now is I do occasionally get a pop on start-up. Backfire sort of but more of a POP.

Don't touch your throttle when starting.