I bought a new quad runner 500 4x4 and have a slight problem. IT BACKFIRES LIKE ALL #ELL!! When i am going fats down the road and let off the gs it pops and booms like nobodies business. I was wondering if there was something i could do do fix this problem. Please help!!

 

Thats common. You may be able to lower it a bit through jetting but its there to stay. Its just fuel that isnt spent that makes its way into the exhaust and is then ignited.