Whaler Central - Boston Whaler Boat Information and Photos

Posted by Lady Celia on 01/25/13 - 5:06 AM

Hello All,
It has been asked before, but every case is ever so slightly different so please forgive me if I am pressing the deja-vu button...
I have a 1981 17' Montauk hull, well, I think it was finished as a Sport but still the same 950 + or - pound hull. It has been re-powered by me with a 2012 Suzuki DF90A 25 inch motor. I chose the 25 inch motor because I built the transom 4 inches higher because I fish offshore and would rather keep the powerhead as high as possible. At WOT, I can just about make 5400 rpms. This is with a Suzuki 20" pitch propeller myself and no load on the boat. The motor has just done 100 hours and I am keen to change propeller to get close to the top rpm recommended by Suzuki - 6300 rpm. Could someone with experience possibly suggest a propeller for me. Unfortunately I live on a tiny and very poorly service island in the Caribbean and trying out different props is not an option.
Many Thanks for any input!
Charlie

Posted by Petrus on 01/25/13 - 5:51 AM

I have the same motor but 20 inch. And I asked the similare question, see this thread:
http://www.whalercentral.com/forum/viewthread.php?thread_id=16431
Seems like a 14" x 18" Stiletto Advantage 4.25 or a 14" x 18" Suzuki SS would be good according to Tom.
I found out I have a 21" alu on mine now and I will ask my dealer to change to a 19" before I even try the 21" as the alu propeller with free choice of pitch is included in my deal.
But I have winter here in Scandinavia now and won't be able to try it before May unfortunatly.

Edited by Petrus on 01/25/13 - 5:52 AM

Posted by Tom W Clark on 01/25/13 - 8:23 AM

The most practical solution would to be to order a 14" x 18" Stiletto Advantage 4.25 which should bring your WOT engine speed up to about 6000 RPM.

If you are using a 25" shaft length model you should have raised the transom 6 or 7 inches and not just 4 inches. Now your motor is dragging badly and slowing you down.

Posted by Lady Celia on 01/26/13 - 5:37 AM

Thanks so much for the replies. I had read the thread, just didn't appreciated you wouldn't be able to test anything until May!! I have the motor raised a couple holes and the cavitation plate is about 1/2" below the hull - right at about where Suzuki recommend. I suppose I could raise it another hole. Where is the best place to buy propellers?

Posted by Tom W Clark on 01/26/13 - 7:47 AM

I have the motor raised a couple holes and the cavitation plate is about 1/2" below the hull - right at about where Suzuki recommend.

That was good advice about 20 years ago but today we like to the see the A/V plate about 1 inch above the keel. That leaves your motor 1-1/2" too low. If you can raise the motor another set of bolt holes (3/4"), do it, but it will still be a bit too low.

If you want a Suzuki propeller, you'll need to order from a Suzuki dealer or buy one off of eBay (which can be a great source for used props).

There are any number of good online sources for the Stiletto Advantage. I can supply you with one as well. Shoot me an email.