Whaler Central - Boston Whaler Boat Information and Photos

Posted by APSamansky on 02/19/11 - 1:30 PM

Hello All:

I have a 1987 17' Montauk with a 2008 Honda BF50A (50hp 4-stroke). The engine came with a Honda aluminum 11.4x12, but the engine would turn 6200 rpm at WOT (200 rpm over spec for the engine) and run the boat at about 30mph. I picked up a Honda aluminum 11.1X13, and now the engine tops out at 6000 rpm (which is within spec) and still runs at 30 mph WOT -- and seems a little more efficient at criuse. Only problem is that the 11.1x13 will easily ventilate when properly trimmed and turning or in chop, etc. Motor is mounted 2 holes up with the ventilation plate a hair above the line of the keel.

So my question is, having read on this and other forums that, keeping everthing else equal, a stainless prop will "grip" better than an aluminum; will a 11.1X13 reduce ventilation while holding rpm and speed? Otherwise, are there any recommednations for a stainless prop that will keep me at about 6000 rpm WOT but be less likely to ventilate when properly trimmed?

Thanks in advance-
Adam

Edited by APSamansky on 02/19/11 - 1:37 PM

Posted by A Little Madness on 02/19/11 - 3:33 PM

I also have a Classic Montauk, 89. When looking to repower, I was advised by multiple sources to go with a 90 hp. I chose the Honda and love it. It has a Honda Titan Solas 13 1/4 15R Stainless Steel Prop, but again, I have a 90. I'm no expert, but I have to wonder if the problem is in fact 50 hp. You might want to talk with a Honda factory rep as I did and see what he advises. Good Luck

Posted by Tom W Clark on 02/19/11 - 5:53 PM

Adam,

As you may know, Honda does not make propellers, they use propellers from other manufacturers in their propeller catalog.

The only stainless steel propeller model for a BF50A in the Honda Propeller catalog is the Solas Saturn, a prop I would not get excited about.

I think a better choice would be a Stiletto Triad or Turbo Hot Shot. I am not exactly sure how the pitches would translate from the Solas props but as a practical matter, 12" is the shortest they make so that's what I would try.

The Stiletto Triad 3.5 in the 10-1/2" x 12" size can be had, with hub kit for less than $200.

Posted by APSamansky on 05/07/11 - 5:45 AM

Thanks again, Tom! After things finally thawed, I got out and did some testing with the prop you recommended. You hit the nail on the head. Gained 2kt and much better grip.