ok i do understand about the counter balance shaft Mitsubishi had them on there 4 cyl run by a small timing belt and it broke and wasnt timed propley it would make the car vibrate in a funney way almst like the muffler was gone .thanks for that i havent spoken to him but ill do some research on it and i only want 5000 rpm or close enough i want a torque engine with the carby i dont like the small primaries and large secs and i have never rejted one i do all my fine tuning using a oxy sensor to get the fuel and air ratio correct thanks for your advice