Why won't my Honda 500 Rubicon ATV start IT backfires when choked?

I'm having the same problem. Try draining the gas from the tank if it's getting old, and put in fresh gas. You may also need to adjust the valves.

IF you have been trying to start it with choke on and it didnot start,your plug is fouled,if plug is not fowled,your carb jets are stopped up.Make sure the inline cut off valve is in on pesition.