Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: 25 hp 4 stroke on 13' sport

Posted by rjrdgo on 08/09/18 - 9:01 PM
#1
Hi folks: I have a 1979 13' sport with a 2011 Mercury 25 EFI 4 stroke. At the 6500' elevation of Durango, Colorado, the engine is unable to plane the boat. I had the engine checked and it runs perfectly, no codes, and proper fuel rail pressure - just not enough steam to plane. This elevation likely costs 4 to 5 hp, rendering my 25 a 20 hp. I have a jack plate on the boat and the ventilation plate is even with the bottom of the hull. The engine has tiller steering and I minimized the weight in the boat. I'm pretty sure I need more power - I don't need a speed boat, but I'd like to get enough speed to get the boat up on a plane. Anyway, will 30 be sufficient or should I look for a 40 hp? I like the 4 stroke cleanliness, but I'm concerned with the weight. The Suzuki 30 weighs 158 lbs, about the same as my 25 Merc. The lightest 40 I've found is 204 for the 40 hp EFI Mercury. Any suggestions?. Thanks.

Posted by Joe Kriz on 08/10/18 - 12:13 PM
#2
A tiller steering 13' Whaler has a MAX hp of 20 and is usually a Standard model.
http://www.whalercentral.com/userphot...lbum_id=16

A Sport model usually has remote steering on a console and the MAX hp on that model is 40hp.
http://www.whalercentral.com/userphot...lbum_id=37

You might consider adding a console if you go with a larger motor.

Posted by rjrdgo on 08/10/18 - 2:33 PM
#3
I believe the boat had a console at one point - the rating plate says 40 hp. So do you think 30 would be enough, or should I just go to 40?

Posted by Joe Kriz on 08/10/18 - 3:00 PM
#4
If you use the tiller, for safety reasons, I cannot tell you to use anymore hp then 20hp which is what Boston Whaler intended.

Easy enough to build a console or have someone build it for you.
We have the plans in our download section.

Posted by rjrdgo on 08/10/18 - 6:00 PM
#5
I plan on purchasing a remote engine and using a console, partially to balance the boat better.

Posted by nhsport on 12/29/18 - 4:53 PM
#6
You are somewhat low on power allowing for elevation but if your engine is running well as you said I would expect some other issue like improper prop is also working against you .

I have a 13 with a pretty old somewhat tired Yamaha 25 that has no trouble getting up on plane
with myself and another big guy aboard (nearly 500lbs for the two of us).

Posted by matt serraes on 12/31/18 - 2:52 AM
#7
I have a 1968 13' with an Etec 30 hp. Plenty of power and speed.

Posted by EJO on 01/03/19 - 7:24 AM
#8
As mentioned what prop are you running and how high up is the current motor mounted as you should be able to get onto plane with the 25HP.
If you are going to remote steering and new power I recommend to go max rated.