I have a 1986 1100 sportster that runs but backfires bad, any body have any ideas where to start it acts like ignition problem. thanks

 

For starters, does it do that all the time when it runs? Just idle? WOT? Hot/cold? Enrichener on/off? Have you checked the plugs, cleaned the carb? Just off the top of my head.

 

Mine will backfire a little on de-acceleration before it's warmed up. It seems to do it more if I push the choke in too soon, which leads me to believe a lean mixture causes the popping. You might want to check for a vacuum leak, or check into the carb jet sizes.

 

Jimmy reminded me, decel pop isn't necessarily a bad thing. Best way to tell if the carb's jetted right is reading the spark plugs.

 

 

In addition to the above, check for exhaust leaks.