Water over motor hinge

Iandayen

Seaman Apprentice
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Jul 12, 2009
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37
I have a 14' Sea King fiberglass flat bottom jon boat with a 68 merc 50 horse outboard on it.

Bot planes awesome, motor is great, but when I get up towards max speed water starts pouring over the motor hinge just above transom, and can flood my transom out in a matter of a few seconds if I'm not careful.

I sort of fixed this by moving the manual trim out to the 4th hole from the boat (was at the second, so out 2 holes) and now very little water comes in, but I notice a difference in the amount of speed it takes to get on plane and the top speed of the boat.

Are there plates made to go there and redirect the water or is this not a common problem?

I can fabricate something I am sure, I was a welder before my computer days but I'm just wondering if there is a reason for this, rather than patch the symptom I'd rather fix the cause.
 

rbh

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Mar 21, 2009
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7,939
Re: Water over motor hinge

is there any way to move weight around to the bow or put your boat on a diet?
is it sittin a little low?
rob
 

Iandayen

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Jul 12, 2009
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Re: Water over motor hinge

Yeah it sits a bit low, I have my fuel tank and battery in the back.

here is a picture of the boat out of water so you can see the general shape.

http://i31.tinypic.com/iekme0.jpg

When moving at slow speeds (not on plane) the rear of the boat sits pretty low, but once on plane it seems to level out nicely but the water comes over my hinge still.

Think If I put some ballast in the bow it would help?
 

rbh

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Re: Water over motor hinge

I was sort of shooten for floatation foam is saturated, or motor was to heavy.
rob
 

Iandayen

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Jul 12, 2009
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Re: Water over motor hinge

how would you go about checking the foam?

And the motor isn't too heavy for the boat I don't think, I can lift it myself (though it is large and awkward to do so) and I'm not a big guy, 6' 170lbs (and like 10-15 pounds is my gut)
 

Bondo

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Apr 17, 2002
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Re: Water over motor hinge

but when I get up towards max speed water starts pouring over the motor hinge just above transom, and can flood my transom out in a matter of a few seconds if I'm not careful.

Ayuh,... As in Spraying over the transom, rather than Pouring,..??

If so,... You're dragging something in the waterflow, or maybe the motor's running too Deep....
 

Iandayen

Seaman Apprentice
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Jul 12, 2009
Messages
37
Re: Water over motor hinge

Here is a pic of water flow/spray that is my biggest concern.

Not my motor, I don't have a camera handy right now, but should give you a general idea.

http://i30.tinypic.com/mcex09.jpg

Most of the water comes into my boat in the red oval area, and the arrows mark how it comes in.

There is a lot of spray also, I'm pretty new to boating, but I thought a lot of spray would mean motor not deep enough but if I read you correctly you are saying it is too deep?
 

Bondo

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Re: Water over motor hinge

Ayuh,... It sounds like you've got a tall transom motor on a short transom boat...
 

Iandayen

Seaman Apprentice
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Jul 12, 2009
Messages
37
Re: Water over motor hinge

how far below my boat should my prop be?
 

tmcalavy

Rear Admiral
Joined
Aug 29, 2001
Messages
4,005
Re: Water over motor hinge

The horizontal plate above the prop should be even with, or within an inch, of the bottom your boat.
 

Iandayen

Seaman Apprentice
Joined
Jul 12, 2009
Messages
37
Re: Water over motor hinge

is there a relatively easy way to raise the transom height?

Like maybe some plate bent and formed to the curve of my transom and then screwed through?


Just went and measured.

Seems my cavitation plate is about 1.5" - 2" below the back of my boat.

Picture here.

http://i31.tinypic.com/np52dz.jpg

Is that low enough to cause that? (this is with the 4 holes out setting)
 

Bifflefan

Commander
Joined
May 27, 2009
Messages
2,933
Re: Water over motor hinge

I fabbed up a a 1 3/4" block (steel) for the top of the transum and then ran a plate down to the top mounting holes inside the motor well. then se the motor on and bloted it up.
This one change made a lot of difference. runs smoother and steers better. not to mention I have more clearance from the skeg to the ground.
 

Iandayen

Seaman Apprentice
Joined
Jul 12, 2009
Messages
37
Re: Water over motor hinge

did you make the block the same width as the transom, or only a little wider than needed to mount the motor?
 

Jeep Man

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Oct 17, 2008
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2,803
Re: Water over motor hinge

You may have your solution at hand, but to answer your question, there are plexiglas shields manufactured. Their advertised use is for back trolling.
 
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