I bought an 04 sportster 883 off of a friend... only 5000 miles and i was told that it ran fine... I have found one problem that i cant seem to correct. When the bike is at idle and i crack the throttle it will occasionally pop/backfire through the carb. I have attempted some adjustment and cleaning with no luck. My friend says that this never happened before. The bike basically sat for approximately one year before i bought it. Any suggestions would help...Thanks

 

how old was the gas in the tank?

 

new gas, drained the old gas, and cleaned out the carb when i noticed the issues.

 

I had a similar issue with an 02. The bike was running lean. I ended up going up one on the main. It took care of it.

 

Thanks for this post guys I was going through the same thing.

 

I had the same problem after I upgraded my AC from stock, and I was already jetted to a 45/180 on my 1200. I was able to get it to quit popping by adjusting the idle mixture screw out and additional 3/4 of a turn or so.

 

I haven't made any changes since I bought it, nor did my friend... The bike has screaming eagle pipes and a stage 1 carb kit... I have tried adjusting the mixture screw, I've gone from 1/2 to 3 1/2 turns out with no change in the popping.

 

Make sure Check your CKP ( Crankcase Position Sensor ) as well They give symptoms of a bad carb .. Went through 3 of them on my 04 Sportster until they upgraded it ..

 

You said you have done some "adjustment and cleaning". Does that mean that you've disassembled the carb and thoroughly cleaned it? An 04 with only 5,000 miles has obviously spent most of it's life parked.

What size jets are installed in the carb?

 

Might want to check for intake leaks, but if you cleaned the carb, you probably already did. Did you replace the seals? Just an idea...

How often does it pop? I know mine will if I push in the enricher before it's fully warmed up and try and crack the throttle.