Help with back firing???

[bkingjr]

I bought the Hooker trouble maker's and had them put on my 08' Pitbull. Thanks again for you guy's making me aware of the great deal!
I had them installed at the dealership. They dyno tuned the bike and were able to get 11 more horses out of her and a lot more torque! The only problem is a constant popping/ back fire upon deceleration. The dealership told me the Hooker performance baffles were too short and there was not enough back preasure.
My questions are: Should I get out of the sweet spot i.e. Rich or lean to help? And... Are there performance baffles that could be installed that would help? Like Varitech?
I will try to post pics soon. The only problems with the pipes as far as installation was a bracket had to be fabricated and the pipe almost sits on the master cylinder, so I worry about extended periods of sitting still.

Thanks to all for the help!

bkingjr

 

[lee]

I'd leave it if it were me. Are you saying the pipe sits right on top the rear brake MC? Is that right?

 

[bkingjr]

Yes it does. There is maybe a 1/16 clearance. I'm not concerned about it. I never sit still / running for long. My biggest concern is the backfire / pop. Any advice on that?

 

[lee]

if its really bad you might have an exhaust leak. If not you could richen it up a bit but why would you do that if it has been dyno tuned. Also, do a search on this subject, plenty of info on this on here.

 

[FIREKILLER!!!]

I just recently had a similer problem. I haad just put on a Martin Bros. Madustas and had it dyno'ed drove it home and it ran great, but after riding a couple of more times I started getting the backfire on decel. I checked in with our BD dealership and he said that you cannot get all of the popping out because I have no baffles. Well after 30 min of trying to explain to him that it gets worse every ride he coul'nt wrap his brain around it any more so I left and came to the all knowledgable BD forums. What I faound out is that after having new pipes installed you need to go thru 3 to 4 warming cycles then retighten your your exhaust bolts because I was sucking in cold air causing the backfire. So went out and my bolts were loose, tightened and waalaa hardly any backfire. Still get a little when I decel hard but hey sometimes you have to let the cages know where you are. Good luck.

 

[LamboV12]

1. Don't worry about the master, you can't get a match book cover in between mine and I have over 10K miles on it - no prob.

2. Turn you idle mix screw slightly to see if you can do it by hand or if you need a small screw driver. Next, find an open road, wind up in any gear and let it de-acel pop. Turn the mix screw counter clockwise (left) slightly and do the run up again. Still got pop? Then turn it more to the left, do the run and repeat until it goes away.

I'm running a Mikuni now, but before with my SS, the mix screw could be turned by hand. I would be able to de-acel and hold the bars with my left hand and turn the adju screw with my right about 30 mph. If you need to use a screw driver, then stop in between adjustments.

The point I want to make is if you a running a straight pipe (no baffle) then you will always have popping, but going rich will mitigate it.

You always want to some baffle - back pressure gives low end torque.