Re: Evinrude 50 HP prop looses bite
On the 50 hp, if it is a twin they built thousands and thousands of them and you can bet OMC, Michigan Wheel and others built tons of props for them. 15" pitch was a common size back when we did a lot of tri-hull group family boating. They're out there.
Remove your prop and with a grease pencil, permanent marker or what have you, mark a line from the center of the hub (spline out to the outer diameter of the prop. Go and do what you do. Then pull the prop and if your lines are no longer lined up, you have spun your prop....prop shops can re-hub it for you if needed or get a new one.
Otherwise you have too much pitch for your application and the heavy load is causing your engine to "ventilate"....suck in air from the surface just above the anti-vent plate.
Course you would have a heads up on this, if your engine was biting clear water and your rpm's weren't up in the operating range then that too would indicate overloading....course with no tach, who knows. There are a lot of cheap tach's out there. My riding lawn mower has one (digital and very accurate) that has a sense wire that just wraps around the sparkplug wire on one cylinder. Surely if my lawnmower has it, it couldn't be very expensive. I didn't check but probably it has a 12v wire and a gnd wire to complete the powering of the digital circuits therein...I never bothered looking under the dash to see.....but the electronics has to run on something and it has hours on it displayed with the key off soooooo it obviously gets power and a gnd.
HTH,
Mark
