...on the coast and shift down. Suggestions?? I know it usually goes away after a trip to HD for service but I'm starting to service my own bike more. Is the popping a detonation in the pipes???

 

Check your sparkplugs. Sometimes that's all mine needs when it does that. New plugs.

 

Popping in the pipes on decel is usually a lean or rich condition that needs to be tuned out with a fuel management device on an EFI bike or re-jet on a carbed bike.

 

1. Could be lean
2. Crack is crossover pipe or loose exhast pipe nuts on the head.
3. Timing may be off.
4. Bad gas.

 

I always thought if the bike was backfiring through the pipes it was running too rich. Can't really tell you much about your situation without a little more information on your bike.

However, you could be tuned perfectly and still get backfire, especially when you are at a high throttle then back off quickly.

 

Its unused fuel hitting hot pipes. So that would be caused by too much fuel rather than too little.

 

I have had trouble with the exhaust coming loose at the heads so I will check that. I will also check the plugs. As far as tuning...I lack that experience...but I look in my manual. But I guess it might have to make a trip to the dealer. I hope not...

 

Agree with others..had this problem and one of the pipes worked loose!

 

True. My bike is EFI and I had stage1 done with a dyno tune and SERT at my dealer. But would still backfire if I ran up to 5000rpm and decelerated in gear. Luckily, I got a nice balanced dyno map from Latus HD that had been done on the same bike as mine with the same mods. Cost $50. Now it runs perfect and I can still make it backfire but have to really work at it to get one pop. Usually backfiring out the exhaust is unburnt fuel (too rich) igniting in the exhaust pipe. But overlean condition will exhibit the same symptom. (don't ask me why as I am no tuner). But now after screwing with my SERT for about a year I have a nice powerful smooth running bike that gets 43/48mpg so I am a happy camper.

 

Did you install new exhaust crush gaskets with your new pipes? If not that could be your issue. Also, did you follow the torque procedure specified in the service manual for tightening the exhaust manifold clamps to the cylinder heads?