Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Proper outboard mounting on Super Sport 13

Posted by donaldpfitzgerald on 10/22/19 - 10:28 AM
#1

Hello,

I recently bought a 1989 13' Super Sport with a 40 hp Yamaha that turned out to have bad compression. I am in the process of purchasing a new Mercury 40 hp outboard with a 20" shaft. The marina has mounted the motor but I have not picked it up yet. My question is that the new motor is mounted so that the part of the motor's mounting bracket that looks like it should rest on top of the transom is raised 4-5 inches above the transom. This looks very odd, and looks like it does not fit correctly. I have searched the internet with no clear answer, but the drawing of whalers of the Owner's Manuals that I see online do not show this raised gap. (These are cover drawings - not schematics.)
So my questions are:
1. Is this normal?
2. Should I be getting a 15" shaft motor instead of the 20" shaft?
3. Why would the boat be designed this way?

Thanks for your help.


(corrected to proper name of Super Sport 13 for clarification)

Don

Edited by Joe Kriz on 10/22/19 - 12:07 PM

Posted by biggiefl on 10/22/19 - 10:49 AM
#2

It is a 20" transom. The reason for raising the engine high is the design of the transom. The engine when vertical trim is far from the transom so you can go higher. The higher mount allows for better performance and less porpoising as well as the engine not getting swamped when coming off plane. You can always lower it but run it first. My Suzuki is all the way up and works great compared to smack down on the transom.

Posted by donaldpfitzgerald on 10/22/19 - 11:22 AM
#3

Thank you!

Posted by Phil T on 10/22/19 - 12:09 PM
#4

The typical recommendation is for the 20" engine to be mounted 2 holes "up". This is shown by the top bolts being in the 3rd hole from the top, ie. there are 2 empty holes up (or above the bolt).

In the old days engines were mounted so they sat on the top edge of the transom. This lead to decreases in performance and handling.

Look at the bolts and tell us what there they are located.

The owner recommendation for props for this model and engine combination include:

10.1 x 14 Spitfire




Posted by Joe Kriz on 10/22/19 - 12:11 PM
#5

What bolt holes are used to mount your motor?
https://www.whalercentral.com/article...cle_id=106