On four strokes, use lots of oil in the crankcase, at least a teaspoon full. A few drops are almost useless. Marvel Mystery oil is not the best choice, no water protection. Use any air tool oil, automatic transmission fluid or (most economical) Rislone in the yellow container which you can get at most Walmarts, Kmarts or auto parts stores. Once you have the oil in the crankcase (thru the crankcase vent), point the engine down and turn the prop over a few times to coat the front bearing with the oil and displace any nitro solvents and moisture there.