Rods

I recently installed a honda GX390 in a golf cart. The engine was purchased new, and never started before it was installed. I removed the gravity flow tank and installed an electric fuel pump with a return line to the tank so the engine dosen't flood. The return line is about 12 inches in front of the carb and has a valve on it to adjust the max flow. The engine runs fine at an idle, but stutters at full throttle. Would removeing the governor help? the rpms can now be controlled with the fuel peddle. Thanks Rod