The bike will crank and idle fine but when you give it gas it starts sputtering and backfires out of the exhaust will not accelerate. This bike only has 4000 miles on it and is bone stock. I have put a new air filter fuel pump spark plugs and cleaned the injection system. Still the same problem. Idles fine and revs fine for about 2 minutes then loses all power and won’t accelerate. Any suggestions will help