Ok. First do one thing. Remove the air cleaner and start the engine. With your finger, push against the side of the governor spring to raise the rpm's some and hold it there. Is the 'hunting' still there? The tab the spring is attached to adjusts the governor speed and being located where it is, is prone to being bumped while mowing, pushed in and lowering the engine speed. If it still surges, this is what I would do... Remove the fuel tank and
carb assy.. Two bolts, one behind the gas cap and one on the end of the tank. Pull it straight off the intake pipe then unhook it from the throttle link. Now, empty the tank and unscrew the
carb from the tank. Clean the
carb with a can of
carb cleaner. Slip the screen off the pickup and make sure it's clean. Discard the pump diaphragm and gasket. Buy a new pump diaphragm kit, part #795083. Clean the top of the tank where the pickup with the screen fits into. Put it back together. Remember to put the rubber diaphragm against the tank and the gasket on top of it then the
carb. Don't forget to attach the breather tube when you're putting it back on the engine. That should fix 'er up. Also, if the rubber
ring and plastic retainer ring came off on the intake pipe when you pulled the
carb and tank off, snap them back in the end of the
carb before sliding it back on the intake. Hope you can make sense of all this. Let me know how it goes. Dwain