My motor runs smoothly at low speeds but won't give full power. When I open up the throttle it runs at what seems like 1/3 power and surges slightly, as if a governor was kicking in. When I leave it alone for 20 minutes, then fire up, it will run at full power, very smooth, for about 30 seconds, then it goes back to the "governor" behavior. The prime bulb seems tight and pumping it doesn't seem to change anything. The fuel is fresh and the fuel pump screen looks clean. ??
