Prop for 1957 Evinrude 18 hp Fastwin

[Deenniiss]

I recently lost power in my motor and was told that I had spun my prop. I went to a boat store and props were lying everywhere. The help seemed as confused as I was. My excuse is Im a first time boat owner. I dont know what her excuse was. There were 9 x 9, 9 x 10 I think as well as others . Is there more than one prop for this motor and if so what are the differences.? I cant read the numbers on my broken prop. I have ordered a used one over the innernet and I m waiting for it to come in. I plan on getting the one thats broke fixed. How much should it cost to get an old one fixed? Any help on understanding props and the differences would be appreciated.

 

[steelespike]

Re: Prop for 1957 Evinrude 18 hp Fastwin

Dennis, Im not an expert but will try to give you a basic lesson in props. Props are measured in<br />diameter in inchesXpitch in inches 9X9 9X10 etc.<br /> Diameter tends to remain constant while pitch<br />will change.Theoretically 9" pitch moves 9" forward in one revolution if water was a solid.<br />There is a loss due to slippage.Less pitch gives<br />more power for heavier boats and loads less top speed. More pitch gives higher top speed but less power.You need to be aware that when using lower pitches it is possible to over rev the motor if the load becomes to light.Think of low pitch as<br />low gear and high pitch as high gear.<br /> Hope this helps.

 

[oldboat1]

Re: Prop for 1957 Evinrude 18 hp Fastwin

If you are lucky enough to have a shop with a bunch of used props around, just take yours in and match it up. The hub/splines have to be identical, and the size and pitch can be pretty much eyeballed if you have the original one to compare it to. I don't think there are too many options to confuse you for that motor -- not a bad thing. Look for a match for the factory original.