Not to derail thread but this is close enough I think. On the ratings, I have an 82, 50 hp 4 cyl but also snagged an 87, 70 hp 3 cyl. So would there be any real increase in performance if I got the 70 running and swapped it?
The 3 cylinder is probably Loop Charged allowing for increased fuel economy. I will say this about my experiences with Cross Flow fueling methods vs Loop Charging methods......the CFs I owned were bullet proof and easy to start after sitting up between outings. My loopers not so.....a lot more picky....course they are made to run on less fuel so they are built that way.......and since fuel is what goes BANG in the combustion chamber, the. more fuel, the easier the bang.
I bought a new Johnson 125 CF back in 1972. Had it for about 8 years with the kids growing up. Went to the lake every week, sometimes twice. Water skiing was its main usage. Changed absolutely nothing on that engine.....nothing, impeller, surface gap spark plugs.....nothing....just put regular gas and OB oil in the tank and away we went....oh and gas was 35 cents a gallon.....I remember that.
On not knowing about worrying about impeller problems if you didn't religiously change it frequently, I used to slalom behind that boat and the engine had dual, round, exhaust relief ports in the top of the mid section and both would be full flowing water at around 30-35 MPH where I liked to ski.....didn't go faster because falls hurt too bad.......
