My 1952 Johnson 25 was taken out first time in several years. Impellor was just replaced, and points cleaned and regapped. I had a newly mixed tank of gas, but I forgot to agitate it (in retrospect). Motor started rather easily, idled smoothly, and ran near full throttle for about 3 minutes when I slowed down. On resuming higher speed, it began running roughly similar to a rich engine with slowing and sputtering every few seconds. No carburator jet adjustment improved it. Leaner led to progressive slowing, and richer resumed rough running. It ran smoother at lower speeds, but not great. Full throttle resulted in slower engine speed than 3/4 throttle. Twice as I returned to dock it abruptly died as if fully throttled back. Restarts were harder, but on starting, still the same behavior. The sediment bowl had some rust particles. Ideas? Could this be slugs of oil rather than oil/gas mixture? The boat is hours from me, so I prefer to know what to do before trying to go back and taking it out again.
