I have a 2008 fxd 3200 miles with V&H slip on pipes and Fuelpak.( mapping has been checked) When the bike is at an idol you hear a sound from the back (maybe from the pipes) that sounds like a marble being drooped in to a pale of water (plop) . My dealer hears the noise but has no idea what it is and thinks there is no harm to the bike. The bike will back fire some times when I let off the gas.

Any help?

 

Check for exhaust leaks first.

 

Checked and can't find any leaks
But thanks

 

If you still have your original heat shields check the clamps for tightness. Check all your mount bolts. If you are up on the rpm's then get off the gas, that's normal for most bikes to decel pop when the conditions are just right.

 

Make sure you're us the latest fuelpak settings
Some of them have been changed pretty dramatically on their website.