I have an old but cheerful Johnson seahorse 2 hp outboard. It runs well but please can someone let me know what the correct mix should be for the fuel/oil. Also, can these older outboards run on unleaded without problems ?
If memory serves me correctly some of the "very old" Johnson's (i.e. pre-1960) ran on 25:1 (petrol/oil).
The one I have had for the last ten years (is that "old"?) runs on 50:1 (petrol/oil).
Engine tolerances and two-stroke oil have both improved in leaps and bounds over the last 20 years or so.
I believe (as opposed to "know") that unleaded four-star gasoline in a 2hp two-stroke engine should pose no real problems. This is because the "lead" was there to help the anti-knock qualities and, as a side effect, protected the engine valves. This is not a problem in small two-strokes.