Hi Andrei, Assuming that there's nothing wrong with your motor, my guess is that the propeller isn't deep enough in the water. From your description of the symptoms the propeller seems to be sucking air, rather than pushing water, which is what it is supposed to do. As a quick test, get all the way aft in the boat - sink the transom as far into the water as you can get it to go (add a case of beer bottles - they weigh more than cans do - all the way in the back of the cockpit, and see if that changes the way the motor functions (a 200 pound friend sitting back there with you would be another way of running the test) If deeper submersion of the propeller in the water improves the boat's performance, you have an answer to your question. The next question is then how to get a lower position of your motor on the transom of the M17, .....a lift motor mount may be the answer. Also, make certain that the cooling water intake of the engine is under water. If the engine doesn't get enough cooling water - you should see a steady stream coming out of the ports under the cylinders - you will ruin your engine. Connie 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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