Originally Posted by slowpoke

Before you buy a kit, check out the following items that the Haynes manual says to check for poor running at idle and low speed. Ignition: Check for low battery, fouled plugs, plug wire shorting, ignition timing, faulty coil and faulty spark unit. For carbs: check for intake air leaks, mixture adjustment screws, carb sync, pilot screw clogged, air cleaner clogged or omitted, choke stuck on, float level wrong, fuel tank air vent clogged, and sticking carb pistons. It also says to check valve clearance. It doesn't say, but we know CBR's, so also check for a stretched cam chain, as that retards valve timing and hurts low end performance.