I did a little exploring before I take the carb apart. The plug is gone so it was taken out my someone. I turned the screw out 1/4 turn. It made a big difference already. It road real nice. Tomorrow whe are goign for a long ride and see how it goes. I'm goign to put plugs in and take the carb off to clean it. I dont want to do it all at once. Then I won't know what actually fixed the backfiring.
I'll keep you posted.

vet,
I've been turning wrenches for years on cars but bikes are new to me. I had cars with carbs that ran like crap and the co/hc where all out of wack. We had to drill out the plugs to get the emissions right. They also ran much better. I quess an engine is an engine when it comes to emissions.

 

Watch Ebay; you can find good used stock type exhaust systems there all the time, sometimes even with a good set of slip ons, you will amazed at how much better your bike runs.

 

i have a 2003 sporster 883 with drag pipes and an aftermarket air filter. what size jets should i get for the best performance?