Whaler Central - Boston Whaler Boat Information and Photos

Posted by kevin nolan on 02/06/07 - 2:28 PM

I have a 1990 88-hp Evinrude on my 1985 Montauk. With a 13-3/4" x 17" propeller on it I can’t get it above 4900 RPM. It should run at up to 5500 RPM at WOT I think. After doing some research I think I should use a 13-3/4" x 15" propeller. What do you guys think? Will this help get me more rpm?

Thank you for any input.

Kevin
Wantagh whaler

Edited by Tom W Clark on 02/08/07 - 7:24 PM

Posted by ratherwhalering on 02/06/07 - 4:07 PM

Kevin, is your current propeller aluminum or stainless steel? What brand of propeller is it? Is the engine mounted too low on the transom?

You can usually pick up 200-300 RPM and several MPH by raising the engine to the second or third set of holes from the top of the engine mounting bracket.

The Stiletto 13.25 x 15 seems to be a good match for that engine.

Posted by rschneider on 02/08/07 - 8:11 AM

What is the recommended length from bottom of V on the hull to bottom of skeg on the motor?

Posted by kevin nolan on 02/08/07 - 3:24 PM

Thanks. I'll check the Stiletto 13.25" x 15" and the recommended length from bottom of V on the hull to bottom of skeg on the motor. Do you know where to check?

Thanks for the input. It all helps.

I think I have a 13-3/4" x 15" I'll try first and I'll let you know when I put the boat in but that's not for a while due to 30 degree weather. Thanks again.

Edited by Tom W Clark on 02/08/07 - 7:28 PM

Posted by Tom W Clark on 02/08/07 - 7:33 PM

Richard,

Forget about the bottom of the skeg. The significant point of reference is the anti-ventilation plate (sometimes called the cavitation plate.) This should be about an inch above the keel with the propellers we use these days.

On a Boston Whaler Montauk, this generally means the motor needs to be mounted "one hole up" with about 3/4" to 1" of space between the motor mounting bracket and the top of the transom.

Posted by kevin nolan on 02/10/07 - 3:24 PM

the boat is still under wraps but il cheek it whin i can thanks

Posted by kevin nolan on 05/24/07 - 6:36 PM

ok so it in the water with a 13 3/4x17 stainless steel prop i got an extra 200 rpms i am up to 5000 a bit over if i trim it out just right im going to try a 13 3/4 x 15 next
i let you know

Posted by kevin nolan on 06/10/07 - 11:38 AM

well i put on the 13 3/4 x 15 it is not a ss but i like it alot it planes out much faster and i got 5500 rpm. if it was an ss and if i raised my engine up one notch i would get that 5800 wot but i am verry happy with the proformace as is.

thank you all for your help
a verry happy boater
kevin