I went riding this weekend for a decent ride and starting getting back fire when I was on the highway. Any idea on whats causing it and how I might fix it?

 

check the header bolts mine were less than finger tight!! i think some how mine worked loose.

 

Also check your spark plugs.

 

What year, model, milage, and mods? Does it do it while decelerating or accelerating, High rpm or low, Hot or cold? You need to put out a little more info to get a decent answer.

 

Thank You, Bob.
+1

 

Also need to know if it is backfiring through the exhaust or carb.

 

+1 Is this bike just out of storage? Old gas? From what you posted I can narrow it down for you. Something is wrong with either fuel mixture, or ignition, or timing, or compression. To get a better answer more information is needed.

 

Sure, check your bike over for a cause.

 

Its a 2004 Night Train FXSTBI. Its the fuel injected model. I bought the bike from a dealership and it was sitting since last riding season. I recently filled the tank with new gas. The only mod is the exhaust. I beleive the back fire is coming from the pipes. It started back firing when I would ease off the throttle at higher RPM or when I down shifted coming off an exit.

 

Sounds like you are "sucking air". So check the head bolts, and around the junction of the slipons to the exhaust pipe. Its called "deceleration popping"