what pitch prop would be on this boat?

[Wildlifedesigner]

I got a 40 HP moter from a 14 foot boston whaler. I placed this moter on my boat had to cut the prop off. I could not find what size the prop. This was the wrong prop for my boat so I would like to know what pitch it may have been. Thanks Bryan

 

[rickdb1boat]

Re: what pitch prop would be on this boat?

On your 1980 Merc 40 with a light load, a 10-3/8 X 14" would be close. Heavier boats and loads would be closer with a 10-3/8 X 13". Of course, this is just a "get close" estimate from a prop selector. I would go with the 13", as you could have it repitched 2" either way to dial it in for proper RPM's. That means you have the ability to go from 11"-15" pitch. The only true way to prop it correctly is by checking the RPM's with a Tach.