converting from long shaft to short

joho5

Chief Petty Officer
Joined
Aug 14, 2008
Messages
456
I have a chance at a 88 Evinrude 25hp. Getting it via trade. I have a small jon boat. Is it hard and / or economical to convert a long shaft to a short shaft?

thanks
 
D

DJ

Guest
Re: converting from long shaft to short

At a minimum, you will need a new driveshaft and possibly a water tube. You will also need to disassemble the lower unit to replace the driveshaft.
 

Woodstock60

Petty Officer 1st Class
Joined
Dec 14, 2008
Messages
238
Re: converting from long shaft to short

Alot easier to go from long to short than short to long as I did. The only hard part is finding the parts cheap.
 

Whoopbass

Senior Chief Petty Officer
Joined
Jun 29, 2006
Messages
653
Re: converting from long shaft to short

You would need to replace the lower leg housing and the lower unit so you would pretty much need a donor motor. I have a 1972 4hp Johnson that is a long shaft but the extension housing is bolted on so it can be removed to accommodate a short shaft but I doubt your 25 has that.
It would be easier to sell it and buy what you need.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: converting from long shaft to short

easier to install a transon elevator, or a jack plate. http://www.iboats.com/Transom_Eleva...32703061--**********.954136221--view_id.40157 or a homemade one,

transomelevator001.jpg
 

joho5

Chief Petty Officer
Joined
Aug 14, 2008
Messages
456
Re: converting from long shaft to short

What about just putting a block of wood or aluminum that sits right under the motor and in between the top of the transom? I mean the motor will still clamp to the original transom, but just have a spacer sitting in there?

would that work?

thanks
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: converting from long shaft to short

a long shaft is 5 inches longer than a short shaft, you need to raise the transom that 5 inches. the motor will not clamp to the original transom. i have shimmed motors but only 3/4-1 inch. 25 hp is a good bit of power, not to be securely attached.

the aluminum brackets should run down to with in one inch of the bottom of the transom. this way you are transferring the thrust where it needs to be. one inside, one outside, each side of the motor.

look at this. http://forums.iboats.com/showthread.php?t=287023&highlight=transom+elevator
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: converting from long shaft to short

Getting back to the motor, unless it is a short shaft converted to long, I don't think you can convert it to short. Doesn't it have a one piece exhaust housing with no 5" spacer? You would have to replace the exhaust housing..a considerable job with $$expense involved. This is what whoop had in mind, I believe.
 
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