Looking for prop - help please

[blueoval78]

Hello everyone,

I have a 15.5ft Bayliner Capri 1500 running a 1988 Force 50HP outboard. My prop is a Michigan Match 10-3/8 diameter, 13.5 degree pitch 3 blade prop. By myself in the boat, I can hit 26 MPH at 5600 RPM's and approx 24 MPH at 5500 RPM's if my girlfriend comes along. I have read elsewhere that with a 15 degree prop and a hydrofoil on the motor it would be possible to hit 28 MPH with 2 people and still get up on plane ok. Now my question is, does this sound right and where can I find a 15 degree prop? Michigan Match only goes as high as 13.5 degrees.

 

[jerryjerry05]

Re: Looking for prop - help please

You start goimg up in pitch your economy will suffer.Try the Mercury dealer for a different prop.Try this site too.J

 

[stepj19]

Re: Looking for prop - help please

Look up piranha propellers on google. They are awesome and make props for all the force motors and if u damage it the blades are replaceable without buying a whole prop. And for 230 bucks u get a prop wrench, a hydrofoil, storage bag, center hub, and 2 sets of blades. So u could get 13 pitch and 15 pitch blades and swap em at the lake in just a few minutes for dif speeds. They also have the blade exchange program during the first 30 days so if the 15 is to much u can exchange those blades
For a dif pitch. Hope this helps.

 

[milehighboater]

Re: Looking for prop - help please

I run a pro pulse adjustable prop on my 75hp. It is a 4 blade composit that can be adjusted +/-2 from a 15. it has been a good prop and you can replace individual blades if you run aground. Nothing will perform like a stainless prop though, but it is an expensive guess to see if you are going to get that extra 2 or 3 mph. you can always look around to see if you can borrow someones 15 for the day, they are quick to change out.

 

[Frank Acampora]

Re: Looking for prop - help please

Try franzmarine@aol.com. Franz MAY have an old Chrysler bronze 2 blade which will fit your engine.

However, at 5600 which is the top of the rated range, I thing you are getting all the speed you are going to get. You can drive yourself crazy changing props but I think you are already right on with your 13 pitch.

Run the numbers: It think your gear ratio is 12 to 21. Figure out your theoretical top speed and then the prop slip with the 13 pitch. Then figure a drop of 500 RPM for the increase in pitch and again figure the theoreticle top speed. Then plug in the slip ratio and figure if the higher pitch will allow more speed-- I think not, and suspect the best you will do is equal your speed now. AND with any extra load besides you, the higher pitch may bog and actually run slower.

 

[jason32038]

Re: Looking for prop - help please

You need a bigger engine. My 15 footer has an 85hp on it. Maybe the 50 is fine for fishing and puttin' around but you need a larger one.