I'm new to Harleys, I have owned my 2012 Wide Glide since May. I have about 2k miles on it. Yeah, I know it's low, that's because I have another bike too and I work a lot.
Well here it goes, I tried to do a search on this topic but I couldn't find any good results.
I installed a Vance and Hines twin slash slip on's on my 2012 Dyna Wide Glide. I have the 103 engine. It's all stock. My bike back fires all the time when I let off the throttle. I guess it's called a decel back fire. It's really getting annoying. The exhaust sounds great when accelerating but once I let off the throttle it back fires a lot.

Any hints? I recall reading something about a fuel pack module on the instructions of the slip on's I bought. I can assume that my bike is running too lean and that's why it back fires every time I let go of the throttle. Will this fuel pack stop this back firing. If so, I'll get it.

HRCH

 

Make sure you have no exhaust leaks resulting from the muffler swap. Provided you don't, you will need to richen up your AF ratio abit. You can do that several different ways. The least expensive would be installing a pair of XIED's. They work in alot of decel popping cases, but they aren't 100%. They didn't work for me. They only other remedy would be some type of tuner. There are a bunch out there, and you'll find a host of opinions on them (just like motor oil). Since all I wanted to do was add a bit of fuel to eliminate my popping, I went with a fuel injector tuner (Dobeck TFI). It allows me to dial in a slightly richer AF ratio to eliminate the popping, gave me better throttle response, and cool the motor down a little. It leaves all other functions of the ECM in a stock config. You'll want to do some research & gather up some coin. Good luck.

 

Thank you for the post. I looked into Dobeck TFI unit. It looks like that is what I would need. However, it looks a little more complicated to set up than I would like. Also, I'm not crazy about disconnecting the O2 sensors. ( I read the instruction) So, I'll just need to look around a bit. Maybe the Fuelpak would work too. I heard power commanders are better left off Harleys, not sure if it's true or just someones opinion.

 

Tuner will go a long way to stopping the decel pop, I use a dobeck and it isn't that bad to install. They offer great support if you need it and for 250$ it does a pretty good job. Just to check it out I took the tuner completely out and the bike started popping like crazy and was real sluggish, popped it back in and popping was gone and acceleration was back.

 

Decel pop is a problem common to most Vance and Hines pipes with the standard baffle.

Do yourself a favor and spend $50 on the quiet baffles. They don't make the bike much, if any more quiet. But, it does make the bike sound much better plus eliminate most of the decel pop.

I had Straight Shots on my ride for a while and the quiet baffles were great!

 

To tell the truth, I like the back firing on my '09 FXDC, stage 1, V&H big shots staggered. Will this cause a future problem? My bike was already set up this way when I bought it with 700 miles on it.

 

Exhaust popping or afterfire (not backfire, which is when you have a fire in the air box/carb/intake/etc.) is both normal and typically not damaging. It results from transitions between rich and lean conditions. Most factory mufflers are designed to make it too quiet to hear, even though it's still happening.

One can reduce it (or make it worse) with tuning. But if you're going to run stochiometric, it's going to happen. But again, it's not a problem, just an annoyance if you don't like the sound.

 

 

What kind of fuel are you using?