I have a gx200 with 2.756 wiseco piston and rod, ambush flywheel isky 310 cam, big valve gx200 head,duel white springs, gage 1.2 rollers,28mm mikuni carb. On race gas. I can not get motor to rev past 5500 rpms. I have tryed everything I know. Now its time to send it to a professional. So please...