I have a 01 400ex, 440 big bore kit, full yoshi exhaust and stage 3 hot cams. First second and third gear are awesome my front end pops up when I hit the gas. But once I get just past half throttle it doesn't have the kick, i can slam the throttle but it does not accelerate that much. Or if I'm just cruising the street before I know it I'll have the throttle all the way down and only doing about 50 60. What could the problem be??

 

Sorry I meant ill only be around 40mph at full throttle