Outdoor Power Equipment and Small Engines - Kawasaki 12 hp surging at high throtle

I have a 12 hp Kawasaki engine in a 165 John Deere lawn mower that is surging at mid to high throtle. It did this last spring and I cleaned the carb out with choke/ carb cleaner and solved the problem. THis time it did not. I took it apart three time and even used a small sewing needle to clean the holes out of the jets and set screws. The proble dooes wuite down a little with a little choke but not completely. I'm fustrated because it sounds like a fuel issues but I don't know where the blockage could be. The fuel filter has not been changed but it runs fine a idle. Any suggestions would be appreciated. ALso it runs a little better at higher throtle under a load.. when mowing.

I agree that it's a fuel problem. Not enough fuel. Try cleaning the carb in a bath type cleaner.