My engine came with a 12 1/4 by 9 pitch three blade prop. It was made for heavy
loads and high thrust. My top speed with the prop was 18.1 @ 5800 RPMs. I
replaced it with a five position four blade adjustable pitch prop.
I tried the 18 pitch and only made 4000 RPMs and 16.3 MPH.
Set to 14 pitch and made 4600 RPMs @15.9 MPH.
Set to the 12 pitch my top speed is 19.2 @5100 RPMs.
My boat is really loaded for cruising with 10 gallons of water, sleeping gear, cooking gear, tools and 13 gallons of fuel.The blades can be changed if broken. The prop was about $139.00 at West Marine.
Replacement blades are $18.00
ProPulse is the brand name.
My FT25B High Thrust Yamaha use's the model 6902 propeller
This prop is completely made of some kind of plastic, so I don't know if it will hold up but I will know in a few months.
The prop has over two hundred miles on it and is still OK as of 7/19/04
1/15/05 The prop has over 1300 miles of use and I still have not broken a blade. I did run up on a sandbar on the Columbia River but no prop damage.