I have a kfx700. It has dual exhaust K&N air filter and a jet kit was just added last fall. I put the size recommended on the and turned them out 2.5 turns as recommended. The quad goes through its range fine but when ran at a constant speed at any point the engine bogs constantly. Any suggestions? Also, when running at a certain rpm it makes a souns similar to a slightly loose heat sheild vibrating at a high frequency or like pan likes being thrashed coming from the front. Any info is appriciated. Thanks all...