shaft too short

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brianprice

Recruit
Joined
Sep 13, 2003
Messages
2
I have a mid-70's 15 HP Johnson that runs fine, but it has a short shaft and the propeller doesnt sit low enough in the water, therefore not planing the boat. I have another motor with a longer shaft, but that one won't run like the other one. Other than cutting a wedge out of the boat and dropping the motor down (which I really don't want to do) what are my options?
 
H

Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: shaft too short

Before I did anything, I'd be sure that the shaft was to short for sure. With the engine setting on the transom the cavitation plate should be about even with the bottom of the boat. If the cav plate is four or five inches above the bottom of the boat, it's too short.<br /><br />c/6<br />Hooty
 
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Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: shaft too short

Brian - You can convert from short to long & vice versa. You will need a shop manual, 5" housing extension, driveshaft, shift rod extension and water pick-up tube. I would look around for a junk engine and swap the necessary parts. The parts may not be that easy to find as this is a popular conversions as many of those 15s (and 9.9s)are desirable for use as sailboat auxiliaries.
 
roscoe

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,921
Re: shaft too short

Or advertise that you will trade engines with someone.
 
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brianprice

Recruit
Joined
Sep 13, 2003
Messages
2
Re: shaft too short

I have an old engine that isn't running right that is a long shaft...do I still need to find all of those parts to make the shift, or do you think that it is something that can be done if I already have both motors?
 
S

Skyhigh

Petty Officer 2nd Class
Joined
Jul 25, 2003
Messages
131
Re: shaft too short

I heard that, you could buy a pill for that now. Suppose to make you shaft longer. LOL
 
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