Best prop?

[Capt dave 258]

Greetings, recently purchased a 21ft pontoon boat with 19inch pontoons. Motor is a 80hp Yamaha, 4 stroke, carbed. Previous owner told me he put that motor on the boat and that it came off of a fishing boat. The prop is a 13x19 and needs replacing. Since the motor was on a fishing boat, I'm wondering if that's the correct prop for the pontoon or should I replace it with a different size?

 

[Scott Danforth]

As with all prop questions

The important ones

What is the max WOT RPM your motor is supposed to be turning

What is the max WOT RPM you are getting?

These are the important two

There are others in the prop sticky

Additionally, is your pontoon motor height set correctly?

 

[QBhoy]

As above needed for sure…but almost certainly, you’ll likely need a good few inches less pitch. Best get the numbers from a test though…before taking a stab in the dark at it.