Mountainmanmyke
08-05-2012, 09:46 PM
hey guys i have a 2003 ds650 and just bought a hmf jet kit with a slip on exhaust with very small restriction and have a k and n air filter with a big gun cdi box. I installed the largest jet that came with the jet kit. I took it out to camp and it sputters mid range and top end. The plugs are black. Should I go a jet smaller? or should I just adjust the air fuel screw and to what? also I was thinking could it be a faulty big gun cdi box? i am not sure, where do i start guys thanks