Check the small oil res, under the cowling. The oil leve must be as full as you can get it. If it's down 1/2" that's just enough for the sensor to light up the horn, The next wave you hit, the horn goes off. That is why trimming the engine will send it off and on according to the angle it's at. Easy fix. Remove cowling, Start engine on water jacket, Let idle, slowly begin to remove cap on small res, (the one just infront of the flywheel) Watch oil level rise, just before spilling, tighten cap. OR REMOVE SMALL CAP,FILL RES. BY HAND UNTIL FULL, REPLACE AND TIGHTEN CAP............ Words of caution. BE very careful when tightening cap, they love to crack and spew oil everywhere.
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mike halfmann