I have a 01 big bear that has a small problem, it backfires thru the carb. I have changed the sparkplug and taken the carb apart and cleaned it out and checked the valve gap. the bike runs fine aslong as your not at idel. has any-one experienced this problem and how did you correct it? It seems to be getting worse the more I ride.

 

Sounds like you need to downsize your pilot jet, looks like your running rich! JMO

 

It seems to be getting worse the more I ride.

With that statement, it would make me think you have an intake leak.

 

Sounds like a lean mixture caused from either an air leak or too lean of mixture screw setting.
Remember the colder the weather gets the worse it will be as well. Start the bike and spray around the intake boots and seal and carb with a carb cleaner and listen for the idle to drop if it does you have a air leak. If it check ok try richening your mixture screw 1/4 to 1/2 turn out more.