My sportster backfires constantly. How can I resolve this problem? I had the carburator cleaned and adjusted, but it still backfires.

Ok, due to different terminology used by different people, I'm going to assume that by "backfire", you mean it pops through the exhaust system when you back off the throttle. On stock exhaust systems which use the "crossover" connector to connect the front and rear pipes, the backfire is usually caused by an air leak somewhere in the exhaust system.

When you back off on the throttle, the mixture is usually too rich to burn in the exhaust system. But, if you have an air leak allowing the scavenging effect of the system to **** air in, the mixture becomes combustable and is ignited by subsequent exhaust pulses.

Check your exhaust system gaskets and replace them if necessary. This should stop your problem. Rejetting the carb may be necessary as well.