I have a cub cadet gt 1554 that I gave next to nothing for. I have replaced a lot of parts on this mower. Been through two new carbs, 2 new fuel filters, new plugs, new air filter, new coils, oil change and filter, new pto and a new fuel filter. It starts right up and runs great. That is until I throttle it up to mow. At full throttle it searches for fuel or surges. It is extremely annoying. I have replaced the gas cap with a new one as well trying to figure out why it's doing this. I have checked for air leaks around the carb base as well as drilled out the jet in the new Chinese carb. That seemed to help a little. Yet it still does it. I am gonna blow out the fuel lines tom after I drain the gas from the tank. Any ideas?
How does it run under load with blades on, also hunting and surging? You are still lean if you have good fuel flow, no air leaks, and correct carburetor. My experience with aftermarket carburetor’s specifically with Kohler engines is sometimes/often a similar result. You will need to slightly enlarge the pilot (idle) jet. Hopefully the jet you already drilled out was not the main jet. It can be a time consuming and frustrating process to try to dial in a carburetor in a case like this.
