Andrei: Your motor sounds very similar to the motor I use.......a Johnson Sailmaster, 4 hp 2 stroke. It will push my 1978 M17 to over 4 knots at only 3/4 throttle. At full throttle, 5 knots plus, but at the expense of greater noise and fuel consumption. Mine is a long shaft, which I suspect yours should be too. I have the older style cutout transom. The prop is buried deep, but even so, will cavitate if I'm standing on the fore deck and a wave rolls through. As for solutions......what Connie said, with the additional thought of checking the shear pin, although I suspect it would not run at all if that was gone. On Jul 19, 2008, at 9:35 AM, Andrei Caldararu wrote:
Hello all,
I have a question on my 4hp Evinrude outboard. Yesterday, in a no-wind situation, the boat (M-17) was barely moving with the power at maximum. Maybe I was getting 2 knots, at best. What did seem strange was that when I moved from one side of the boat to another, the prop seemed to rev up, as if just by shifting the weight and lifting slightly the motor, the prop was about to cavitate. As it is mounted right now, on the original (1982) motor mount, the motor is in the water up to the bottom cavitation plate, just above the water pump intake.
Is the problem the motor itself, or the fact that the motor is not deep enough in the water? It seemed to run fine except for the lack of power/speed. It is the original motor that came with the boat, 1981 Yachtwin, the boat is 1982 M-17.
To give you an idea, with my Compac 16 (lighter, 1100 lbs versus 1600, but still), a Johnson 3hp was pushing it at hull speed with only 60% power.
Thanks for all input,
Andrei.
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