okay i have an 05 bf 650 sra. so i just rejetted my carbs and put new needles in, replaced the plugs, cleaned the air filter, changed the oil, changed the anti freeze, changed the belt and reset the belt light. but for some reason whenever i get into the gas it hesitates and wont build up speed...

There is a lever on the right side of the engine and I was wondering what its purpose is. I have a 1995 Bayou 300 2x4.