Ive got a JD LX188 with a kawasaki v-twin liquid cooled engine. At low rpm the engine surges from high to low rpm. When the throttle is open all the way it doesnt. After running it and mowing for 10 min, it starts to surge even at full throttle. What could be causing this? Plugged jet? weak fuel pump? Dutch

The problem could be a plugged air bleed in the carburetor, or you may have a small air leak in the intake, that get worse as the engine heats up. Check the carburetor mtg bolts as well as the intakes.