Hi. I just bought a used snowmobile and the motor doesn't run well. I think the carb needs to be cleaned. The previous owner didn't run the sled for 2 years and left gas in the tank. The motor does not stay running unless you are working the throttle, and when it is running, it is backfiring and wants to die out. Can I clean out the carb myself or should I take it to a shop. If I can clean the carb, how is the best way to do it? I already tried to spray a can of carb cleaner into the carb without much noticable results.