What Prop do I need?

[TD_Maker]

I am trying to figure out which is the correct prop for my boat. I have tried a couple of different props for testing before I make the investment in a new SS Prop. I am hoping one of the "Prop Experts" will jump in and give me a hand. Here is what I know so far: Testing was done with full gas tank (20 Gallons) and just me in the boat.

1. 17 ft McKee Craft CC
2. 2003 Johnson (Bombardier) 90 HP
3. Gas Tank Under Center Console
4. . Michigan Wheel Aluminum 14 x 13 Pitch: 5800+ RPMS
5. OMC Aluminum (Cupped) 13 1/4 x 17 4800 RPMs

Can anyone tell me what prop I need to be running?

 

[jestor68]

Re: What Prop do I need?

Have you tested with a 15 pitch?

 

[TD_Maker]

Re: What Prop do I need?

Not yet. I was thinking I may have to go that way, but a 15 pitch prop is a little harder to find. There is a huge dealer around here with hundreds of new and used SS props, but they do not have a 15 pitch prop on hand for testing.

I thought if I went with a slightly smaller diameter prop it would do the same thing....that how I ended up with the 13 1/4 x 17 OMC prop....which I tested today. I need about 700-800 more RPMs Would like to be at 5500 - 5800 RPMs.

 

[jestor68]

Re: What Prop do I need?

Iboats carries a number of 15" props to fit your motor. A Solas 15" is just $95 and is probably the best performing aluminum prop around.

A slight change in diameter has little effect compared to a 2 inch change in pitch. The 15" pitch is what you need to get you up to around 5300 rpm(your motor's hp is rated at about 5000 rpm).

 

[jestor68]

Re: What Prop do I need?

Deleted due to iboats wierd server that likes to post things twice. :facepalm:

 

[TD_Maker]

Re: What Prop do I need?

Jestor,
According to my factory service manual, my motor is producing 90HP at 5500 RPM. Full throttle should be between 5250 and 5750 RPMs. You still thinking 15 Pitch?