I hope this isn't a stupid question, but I have my 2000 450 ES almost running right but it backfires when you let off the gas. I have read that you need to adjust the pilot screw, or clean off the tip, but do you have to take the carb off to do this or can you just unscrew it out, clean it, and screw it back in all the way and back it out 2.5 turns or so?