Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Performance with a 40 HP 2 Stroke Merc on 1989 13' SS

Posted by zach_gaucher on 06/26/08 - 7:03 PM
#1

I just bought this boat and am wondering what the top speed will be and how the boat handles with that kind of power.

Posted by John Fyke on 06/26/08 - 7:13 PM
#2

Dude thats all you need. That boat will scoot. B)

Posted by chrepp on 06/26/08 - 7:56 PM
#3

I have a 71 40 hp Evinrude on my 68 13 Sport and it has to go about 30-35mph with two people and handles it well. Some people have put 50 hp engines(2 stroke=lighter) on their's and don't have any problems from what I have heard.

Posted by MW on 06/27/08 - 2:06 AM
#4

some thing's were ment to go together, a 40hp and a sport 13' is one of those thing's !
mw

Posted by CES on 06/27/08 - 5:05 AM
#5

I'm running a 40 hp in my 13' and couldn't be happier with it....plenty of performance.

Posted by moose on 06/27/08 - 7:47 AM
#6

Zach,
What prop do you have on the Merc? That should tell you what speed to expect. Do you have a tach?
I agree with MW, that 40 is a perfect match. I have a Nissan 40 and with three adults, 2 ice chests, and fishing gear I got up to 32 mph at just over 5100 rpm. With just one it tops 40 mph trimmed out at around 5700 rpm. I have a 13" pitch prop.
Mike

Posted by dburr on 06/27/08 - 2:51 PM
#7

If you want to figure out speed check out this link: Propeller Calculator

Slip for small planning hulls is anywhere from 20-35%. The gear ratio should be in your engine manual, if not you can figure it out by turning the engine over by hand (easiest/safest with plugs out) and count the rotation(s) of the wheel. The pitch of the wheel should be stamped on the hub, ie 9x13 is 9 inch diameter, 13 inch pitch. If the wheel has any cup to it (uniform roll on trailing edge) that increases the effective pitch, to what degree I do not remember, just use the stamped number… Dave Gerr’s “Propeller Handbook” is a great source of info for the “closet geek” in all of us..

As far as it being a good fit, the data plate says 40 hp max. 33CFR183.53 is pretty specific (as Fed talk can be) about horsepower limits.. You hang more than you are rated for and get caught, more than flies will hit the fan…

I had access to 13 with a 25 as a kid and always wished for more. I DREAMED of a 13 with a forty.. Remember (are you old enough?) that bullet shape late 60’s Evinrude white top blue bottom forty? Or the black and sliver mini “tower of power” Mercury? What a great combination..

Get the right wheel and you will be happy and the boat ought to go like a scared cat. Unless of course you really want a bigger boat;)..

Dave

Posted by Joe Kriz on 06/27/08 - 3:12 PM
#8

I had a 13' with a 35hp Evinrude on the back. It would pull me out of the water with one ski on if I dragged a foot.

I always did want the 40hp though just for those flat days. I certainly wouldn't go anymore than 40 hp though...

Posted by zach_gaucher on 06/27/08 - 5:41 PM
#9

dburr- Originally I wanted a more classic whaler (pre 72') but I couldn't find any good deals and I really got an incredible deal on this boat.