I just purchased a 09 Ultra. I was told it has a stage 1 and it has a custom tuner on it. When starting it up it sometimes backfires 1 or 2 times. Super loud! Afraid the neighbors think I am shouting my pistol or something. Do you all have any idea what may be causing it to do this? It runs fine.

 

What kind of pipes? It's not running fine if its backfiring.. Need to tweak the tune a bit.

 

I have Jackpot pipes. The backfiring only occurs when cranking, not all the time but maybe 2 out of 5 times. When the bike is running, there is no backfiring at all.

 

Too rich on startup maybe? Unburnt fuel in the collector? Would have to look at the tables on your tune.. But thank you for your service Sir!

 

My '14 SG does the same thing sometimes.

 

My 2004 RK does it sometimes

 

Check your plugs. The reason I say that is because when I went to the local HD dealer he sold me on HD screaming eagle plugs. And when i would start it up sometimes it would back fire really loud. I checked the gapping when I put them in the first time but still backfired. I went back and got the factory plugs no more problem. Oh ya my bike is 2011 RKC

 

I'm just throwing this out, I am no fuelie expert, I am wondering if it has the feature that lets the bike turn a couple of revolutions before firing. Maybe that is turned on and dumping fuel in exhaust before it fires?
Also is the ignition duel fire/single fire maybe turned to dual fire.

 

Check your compensator and make sure it's still tight. My 05 came loose and that was what mine would do when starting it up not all the time like you said.
Russ

 

There maybe some validity to the SE plugs. I have them in my FLHTK and don't have a problem. I have noticed that the majority of the bikes that I hear backfire are the CVO's. Some have tuners and some don't. I think they all have SE plugs. I have heard others do it, but not as regular as the CVO's. Come to think of it most that do it have true duals. It could be they are firing both plugs at the same time when in Start mode. I know some of the after market ignition modules do that and go to single fire when running. Just guessing. Put new tune on a 2013 CVO last week and went to start it and it popped so loud my ears were ringing. Was inside the shop. I thought a gun went off.