Yamaha F115 What Prop Should I Get ?

[macjsm]

For my 115 HP Yamaha 4-stroke, 17 1/2 foot Larson
What prop should I get, What size and pitch, what manufactor ?
I had a 13 1/4 x 17 Yamaha Prop, the boats top speed was 38 MPH.
I put a 13 x 19 Michigan Match prop, and top speed dropped to 36 MPH,
What happened I should have increased speed but didn't, does the
make of the prop make a difference ?

 

[WillyBWright]

Re: Yamaha F115 What Prop Should I Get ?

What are your full throttle RPMs? You want to prop it to reach 6000 or you don't develop full horsepower. Overpropping can decrease speed. Brands of props make a difference, styles of props make a difference, materials of props make a difference. Pitch is a theoretical figure assuming perfect conditions which don't exist in the real world.