I am getting popping sounds on deceleration from my pipes (you can see in my picture- Bub jug Huggers, max flow pipes, almost free flow) from about 5mph above when I shift to when I shift or in simplier terms, from 1/8 throttle to no throttle when I am riding. For example from 35 to 30 in 3rd gear. Anything above 5mph doesnt pop at all, everything is perfect. Its just at slower rpms. Theres no exhaust leaks (I double checked and tighten everything to be sure). I also adjusted the fuel to air ratio so that its running more rich and im pretty damn sure its almost perfect but not certain. My question is... Am I still running alittle bit lean? Or is this popping sound common for long pipes which I heard from somewhere?

 

I guess out of 70 people no one knows anything?

 

I have drag pipes (long pipes, as you put it) but not your particular brand or design, but I don't have any popping like that. I was always told it was a sign of fuel/air mixture being accurate. Has your carb been jetted? The bike been dyno tuned?

 

Thank you for the reply. My bike has a carb and after installing the pipes, I noticed that the previous owner has already worked on the carb. So before rejetting (not knowning if he already did before or not), I adjusted the air/fuel mixture screw based on feel, sound, responsiveness, temperature of engine, and symptoms of both rich and lean and im pretty darn positive I got it tuned in pretty good. I have heard that making it more rich will get rid of the popping sound but has no effect on performance. As long as the popping sound does not indicate being lean or something then I dont care that much

 

I've got mine running a little rich, that might be why mine doesn't pop. ??

 

And I got mine running alittle lean.... Hmm interesting haha, but yea maybe, im going to make it more rich today and will see what happens

 

do you have baffles in the pipes? I would also check what jets are in the carb

 

How do you plan on making it richer? Playing with the mixture screw really isn't how you get rid of decel pop.
There is a procedure for adjusting the mixture screw and it has nothing to do with correcting for decel pop.
What size pilot jet is installed? You probably need a #45.

My 04 1200 with the same Bub Jug Huggers doesn't have any decel pop.
BTW, the Bub Jug Huggers use a step tuned header, they're not like drag pipes.

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I think the popping is caused by fumes being burned in the pipes rather than in the cylinder. A lean mixture burns more slowly therefore fumes can make it into the pipe before getting burned. richer mixtures burn faster and don't let fumes go into the pipe. playing around with the mixture screw can make it richer and correct the problem

 

Yes I do. They are high flow though, so fumes go right through