Prop for 1970's Starcraft Islander/165 Inline 6 Mercruiser I/O?

[bikesnboats]

I'm hoping that you'all can suggest the right prop for this boat (1970 Starcraft Islander with 1973 Mercruiser 165 Inline 6 engine and outdrive) which will be optimized for Pacific ocean fishing with occasional trips to mountain lakes. I'm hoping to minimize trial and error (to which I seem particularly inclined!).

Thanks!
bikesnboats

 

[steelespike]

Re: Prop for 1970's Starcraft Islander/165 Inline 6 Mercruiser I/O?

If the boat is presently in operation get us the prop size and the lightly loaded wot rpm and speed by gps.

 

[IamCanadian]

Re: Prop for 1970's Starcraft Islander/165 Inline 6 Mercruiser I/O?

If the boat is presently in operation get us the prop size and the lightly loaded wot rpm and speed by gps.

x2 Finding the right prop is a science, If you can give us your current prop diameter and pitch along with GPS speed and engine rpm @ wide open throttle, we can do the math and figure out prop slip, engine load and from there we can suggest what prop would best fill your needs. If you only guess at speed and rpm, we can only guess at a prop....that turns into trial and error.

Remember the more accurate the info, the more accurate the answer.

 

[bikesnboats]

Re: Prop for 1970's Starcraft Islander/165 Inline 6 Mercruiser I/O?

Thanks friends! Pulling floors and interior prior to complete restoration and later installing a 1973 Mercruiser I/O from a donor boat I've bought to replace the dead 140 4 banger and outdrive in the engine bay. I was just wondering if someone had discovered the magic propeller for that boat/motor/outdrive combination. Ok so WOT should give 3800-4200 RPM. I've got it. Thanks again.
bikesnboats

 

[jestor68]

Re: Prop for 1970's Starcraft Islander/165 Inline 6 Mercruiser I/O?

Your 165's rpm range is 3900-4300 rpm. The gear ratio should be 1.65.

Try the Quicksilver 15-1/2 X 18 first. If that's too much, drop to the Solas 15-1/2 X 17.

 

[bikesnboats]

Re: Prop for 1970's Starcraft Islander/165 Inline 6 Mercruiser I/O?

Thanks jestor! Just the advice I was looking for. I was hoping some old (as in 'experienced') "Islander" skipper would have a ready answer.
bikesnboats