A friend of mine has a 2003 HD Sportster 883>1200(8k miles + -) and I mentioned to him he should have his bike checked because of it backfiring. He said the last time he had it serviced for an oil change they said it was nothing to worry about because of Stage 1 setup and the ethanol in gas. I say it's a concern.......not normal.

Welcome your opinion and will forward your opinions to him.
Many thanks!

 

You need a lot more detail about when it is occurring to determine if it is acceptable or not.

 

Not acceptable IMHO! Could be as simple as a slight leak in the exhaust or inlet manifold, but I wouldn't put up with it and would sort it out.

 

This makes perfect sense.
I did forget about the slight leak in exhaust or inlet manifold.
I thought possibly since it is a carb model that since he had taken it in for a tuneup and oil change that they could have adjusted the carb and or timing wrong.

 

A bud of mine is an HD mechanic and he once told me if ya have excessive backfiring when ya let off the throttle it can be as simple as your carb is set up to rich. Check your plugs and see if they are runnin a bit rich. Darker color or wet lookin-rich. Nice brown paper bag color-nice. Whiteish lookin-lean. I know this isn't over technical, but most of us don't have a bunch of tech equip at home anyway. This is a good place to start and isn't too invasive. If that doesn't cure the problem, ya might want to take it to a shop and have em look at it.

 

Agreed.

Sporster "sputtering" provides this forum a major topic. Remember, you've got an unheated manifold feeding two large volume cylinders, cold starting and running performance is always going to be sketchy.

John

 

first , describe your problem ...you say backfire..
that is spitting back through the carb/efi aircleaner .

exhaust pop (called "stackfire" in the aviation world)
is popping of the exhaust pipes..

two different symptoms...two different reasons..

 

What John Harper said. Yepper.