You may have to go to a SAE 40 wt. oil to get it to seal properly. Some knurl the skirt to enlarge it and have it hold more oil. Those small third port outboards are very sensitive to crankcase leakage at low speeds. Some won’t run with a propeller attached. With the carburetor next to the exhaust they can vapor lock in hot weather. When everything is right, there is no motor better. . .
