20" to 15" Mercury 15hp outboard conversion

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Split Decision

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Would anyone have an idea on the approximate cost and feasibility for converting a 2001 Mercury 15 hp 2 stroke outboard engine from a long shaft (20") to short shaft (15")?

Thanks,
Mike.
 
Feasible, yes. Cost depends on what you can find in the way of parts. You might have to buy an old wreck and cannibalize it.

To be honest I'd consider bolting a 20" piece of 2x10 to the transom of whatever boat you're using.
 
Going from 20 to 15 is easy compared to going the other way. I'm pretty sure all you need is the bottom end and shift shaft...but willie's way is easier.
 
I have a Mercury 310 Inflatable that I use on davits with our 328 Four Winns. I also have an in-expensive 14' aluminum boat that I use for muskie fishing and towing my 11 year old son around on the ski biscuit.

I wanted to use a Mercury 15hp 2 stroke outboard that I could use between both inflatable and 14' aluminum boat.

Long story short (no pun intended :)) I now own a 2001 Mercury 15hp 2 stroke but 20" long shaft outboard. Guess I'm kinda screwed using this on the inflatble unless I do the long to short conversion. Could do something with making an adaptor for the aluminum boat.

Thing is this 15 Merc is mint. Wanted to work with it, but maybe I'm just better to sell it and get a 15 short shaft?

A little surprised there is not a for lack of a better term a long to short shaft store bought transom converter.

Mike.
 
Thanks for the suggestion Willie. Charlie it seems the cost of the parts required for conversion could be in the range of $400.00 - $500.00 before labour.

What about if I took a 16" length of PT 2 by 6 and made it a 16" length 2 by 5, then place this 2 by 5 directly on top of the existing 14' aluminum boat's transom. Then cut a piece of say 3/8" flat steel 16" by 12" and then thru bolt the cut the piece of steel, PT chunk of 2 by 5 and the boat's transom. I would put the steel plate of backside of aluminum boat.

Would you feel this would be a reasonable solution as well?

Thanks,
Mike.
 
Really I wouldn't bother with the steel plate. IMO it's overkill, heavy, and it'll rust. For smaller motors up to 20 hp or so I'd simply use the 2x, properly sealed.

Or you could put the block on top of the transom as you describe, and put a piece of 1/8 aluminum on the outside AND on the inside, assuming the clamps on the outboard would span the thickness. A "sandwich" of two pieces of aluminum would be plenty strong enough, won't rust, and will "go" with the aluminum boat. There's the "adapter" you want. Actually I think you CAN buy them but I have no idea where.

There are lots of ways to make it work, it really depends on how pretty you want to make it.

Here's a manual jack plate that should work too: http://www.bobsmachine.com/Mini-Manual-Jack-Plate-MMJ-0-40-HP-Max-standard-width-100-200100.htm
 
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