re: Push Mower problem: need help

The easiest and often the most effective thing to do is drain the carb float bowl. Old, stale fuel is just sitting in the bottom and even filling the tank with fresh gas and fuel treatments won't flush the old stuff out unless you plan to keep pulling on the starter rope for 20 minutes. I've put fuel shut off valves on every 4-stroke piece of equipment I have and that's how I shut down the equipment after use now. If the lawn mower has a deadman bail then keep a clamp or 550 cord to keep it engaged until the engine idles the fuel out of the carb. My Honda lawn mower would have fits sometimes if I let it sit for more than a week between mows, never had the surging issue when running the carb empty though.