My Toh 6hp 4 stroke wouldn't idle and was hard to start. it had less than five hours on it so I brought it to the dealer who cleaned the carburetor and advised me to always run the gas out of the engine before putting it away. I do this and also use fuel stabilizer, run ONLY ethanol free gas, and every two months or so, If I haven't used much gas from the tank, empty the "old" gas into my car's tank. Motor now starts on the first or second pull, even after being idle for two or three months. BTW, Tohasu makes most of the smaller Mercury and Nissan motors. Parts are mostly interchangeble, but cheaper under the Tohatsu brand.