Motor mount height- is this normal?

Matrex

Seaman
Joined
Aug 2, 2008
Messages
54
I am taking my boat apart... taking pictures of everything as it comes off. I just noticed that the motor seems mounted very high to my inexperienced eye. Just looking at the way the mount is made I would have expected the bracket hook to wrap directly over the transom - this seems so high.

Perhaps this is a function of transom height? Attached a photo of mine, and a diagram from an install manual I found (different brand) that depicts what I would have thought as "normal"

IMG_0130.jpg


motordiagram.jpg
 

HybridMX6

Senior Chief Petty Officer
Joined
Oct 22, 2008
Messages
676
Re: Motor mount height- is this normal?

I doubt it's an issue unless you noticed any sort of cooling problem. I am sure I will be corrected if I am wrong, but transoms differ a little bit in size. I say that because my boat has a 20" transom, but my long shaft Johnson sits way to low in the water on it. I can't do anything about it right now, but I am sure it could be raised at least 1" and not cause a problem. My cavitation plate is just over 2" below the bottom of my boat, and all my other boats/motors I have had it has always been pretty much directly aligned with the bottom of the boat, and I've never experienced any sort of cooling problems with any of them.
 

freddyray21

Commander
Joined
Jun 10, 2006
Messages
2,460
Re: Motor mount height- is this normal?

it should rest on the transom. Somebody raised it for better performance which is fine, but you need to put a spacer on top the transom for it to rest on. Not a good thing to leave it like it is.
 

Matrex

Seaman
Joined
Aug 2, 2008
Messages
54
Re: Motor mount height- is this normal?

Thanks FreddyRay. What would one use for a spacer?... I am replacing my transom & stringers so this is a perfect time to do this too.

So much to learn...
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Motor mount height- is this normal?

No need for a spacer, it'll be fine just like that.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Motor mount height- is this normal?

spacer not required the engine is bolted to the transom. this is called proper set up technique. the ideas is the get the AV Plate (flat plate above prop) to the proper height, compared to the bottom of the boat. that is why your motor has so many adjustment hole on the transom bracket. the older clamp on motors due need the spacer under them.
 

HybridMX6

Senior Chief Petty Officer
Joined
Oct 22, 2008
Messages
676
Re: Motor mount height- is this normal?

Yeah, I wasn't thinking of the gap left in there. That's why I can't do mine right now, no way to lift the motor and nothing to use for a spacer. My boat is aluminum, so I was wanting to use a solid block of aluminum and have it welded onto my transom to add strength. I only have one set of bolt holes on mine (manual tilt model), so if I raise it that's going to put the holes pretty close to the top of the transom.
If you are rebuilding the transom, I'd build it that height if that's what you want to do. Measure it out, from bottom of the transom to the bottom of the motor bracket where it should rest on the transom, and use that for a new transom height.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Motor mount height- is this normal?

this is fine in concept, but real circumstances, it does not necessairly work. i just went thru this with my pontoon boat. the previous owner put a long shaft motor on a short transom, so for it to be correct i had to raise it. i built the transom to the height i thought was correct, but the motor ventalated (too high). i then had to remove the motor and cut the transom 1 1/2 inches, and reseal the top. now everything is fine.

sometimes a jackplate or transom elevator are better cures.




 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: Motor mount height- is this normal?

I would not mess with the transom's configuration one bit. Good chance that someday the existing motor will no longer be on that boat and the next motor may require a different set-up. It's better to have the option to be able to go down a notch than to be stuck with a too-high setting. As was noted by DHadley, no spacer or support is needed - the stresses are at the bolts attaching the motor to the transom. Those little overhanging tabs are simply for when the motor is not actually attached to a boat so that it will sit on a rack or stand without falling off...
- Scott
 

freddyray21

Commander
Joined
Jun 10, 2006
Messages
2,460
Re: Motor mount height- is this normal?

probably work fine, but for my piece of mine I would put a spacer in to take the load off of that bend. Just my opinion.
 

tmcalavy

Rear Admiral
Joined
Aug 29, 2001
Messages
4,005
Re: Motor mount height- is this normal?

I know the others are right, the bolts are carrying the load of the motor, but I'm with freddyray...put a simple wood spacer in there IF it bothers you. It would drive me nuts, but that's what my better half says about me, too. I prefer the term 'filberts.'
 

mthieme

Captain
Joined
Oct 6, 2007
Messages
3,270
Re: Motor mount height- is this normal?

Ditto.
I use a wood spacer needed or not.
 
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