Weird motor mounting?

bananaboater

Ensign
Joined
Jul 27, 2009
Messages
932
Move thread if necessary but seems like a non technical motor question.

Where to start? My Merc 400 is/was mounted on my 20" unusual transom height Starcraft Jet with a wood spacer. Here is a detail. The wood spacer holds the motor up so the bottom bolts meet wood at the bottom of the internal transom.

IMG_0616-1.jpg


This transom board does not extend all the way down to the notches in the brackets (dark band is just a stain). Notice the bottom mounting holes for the motor are about 1 or 2 inches above the bottom to give them something to hold on to. The top screw mounting pads are just grazing the aluminum cap.

IMG_1115.jpg


The bottom of the mounting bracket is slotted so the motor COULD be lowered not quite as much as the wood spacer but a lot.

My question is when I remount the motor should I let it slide down as far as it will go in the slots and then fill in the gap where the wood is with a much thinner piece of aluminum? That will lower the upper screw clamps by about an inch and of course the whole motor. The teleflex steering might have to be adjusted then.

Here is a long shot of the teleflex set up, sorry did not take a detail before un mounting the motor.

IMG_0697-1.jpg


I cannot exactly figure out why with the slotted mounting the PBO did not let it slide down and fill in the gap like I want to. The other option I am considering is keeping it the way it is with a 1 inch aluminum spacer instead of the wood.

Any ideas? :eek:
 
Last edited:

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,079
Re: Weird motor mounting?

Ayuh,... Nice pictures of everything But what needs lookin' at...
I suspect it was raised to allow the motor to run better, Higher...

It's ALL about the propshaft to keel line interface... Higher is Faster, til it gets to Blow-out heights...


Btw,... resize your pictures to 640x480...
Nobody likes to side-scroll to read your posts...
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: Weird motor mounting?

The motor was most likely in that position so it would be at the correct height for performance, lowering the motor will probably slow you down and cause water to splash up around the lower unit. You can replace the wood spacer with whatever you want, or just leave it out, it makes no difference, it only really makes it easier to mount the motor by having something for it to rest on while its being clamped and bolted in place.

It looks like this combination and setup worked for a very long time, so unless you have reasons to change it, it should continue to work well in the future too.
 
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