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Short or long shaft?


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7 hours ago, glen said:

Or.  Make boat transom higher. 

place engine on boat.  Mark holes for mounting engine on boat.  Drill out holes.  Buy two pieces of 1/4 stainless steel one for each side of transom that are high enough.   Fill void with wood.  Go fishing.  

The above would be the best fix for this. IMHO Fill in the transom where it dips down just as Glen said. 

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Had a friend do this, as he was given an all but new long shaft for free. Didn't take much time to decide to build up the transom and it worked great. He fished that boat for years. He built the transom up so that the cavitation plate of the motor was level (well maybe just below?) the keel of the boat. 

Dan..

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That boat was originally a Long shaft boat, and someone has cut the transom to fit a short shaft motor. The second step down and the gusset reaching the edge are 2 giveaways. 

I'd rip it all out and replace the transom wood to the original profile ( the pic with the red line on it). It will cost you one sheet of 3/4 plywood, paint ( sealer) and time

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That boat was originally a Long shaft boat, and someone has cut the transom to fit a short shaft motor. The second step down and the gusset reaching the edge are 2 giveaways.  3rd giveaway is that no one makes a 40hp short shaft motor, therefore no one will rate a short transom at 40hp

I'd rip it all out and replace the transom wood to the original profile ( the pic with the red line on it). It will cost you one sheet of 3/4 plywood, paint ( sealer) and time

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I'm suspecting that wood is probably 1 inch thick, I did one for a friend.  Take that whole piece out,  use it as a template and fill in between the red and blue lines.  I would laminate two 1/2 inch sheets with gorilla glue and clamp the %^&*# out of it.  Then apply several coats of the real wood sealer, not the VOC kind, it's junk.  Try to find Teak Sealer, not teak oil.

I'll agree with Dan if you can find some wide planks of oak, that would even be better.

Edited by Fisherman
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43 minutes ago, Fisherman said:

I'm suspecting that wood is probably 1 inch thick, I did one for a friend.  Take that whole piece out,  use it as a template and fill in between the red and blue lines.  I would laminate two 1/2 inch sheets with gorilla glue and clamp the %^&*# out of it.  Then apply several coats of the real wood sealer, not the VOC kind, it's junk.  Try to find Teak Sealer, not teak oil.

I'll agree with Dan if you can find some wide planks of oak, that would even be better.

I did a transom on a smokercraft last year.. it was 1.5" thick.. so 2 x 3/4 plywood and the method you explained..  go all the way across the boat with the grain horizontal, don't try and patch a chunk to the existing piece. The transom will flex under torque so the wood needs to flex and not break.

 

laminated wood would actually be stronger than a solid piece ( if you could ever find one big enough) as it would flex a bit.  A solid hardwood piece will snap easier if flexed.  My first ever transom I replaced,  I used a piece of hardwood ( cherry I think)  the last time I had the boat out, the transom had alot of flex, so I think the wood inside is compromised .. You have to ask yourself, why do boats come with plywood core transom rather than hardwood or even just solid aluminum?

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Yeah...plywood is definitely the way to go. Can't beat Douglas Fir Marine Grade plywood....sealed with thinned out 2-part epoxy resin. Glue and then  clamp together the two 3/4 inch sheets with the epoxy too. A little pricey and extra work to brush on the epoxy but you won't regret it 10 years from now.

If you want to go all out...sandwich the sealed and glued plywood between  two sheets of  .100 guage aluminum. Cap the exposed top edge of the plywood with same...

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thanks guys... seems like a bit of a project.. which begs the question - why not just sell it and buy a shorty?!  I guess the thought of changing the transom seems like overkill.  It's interesting that one or two of you pointed out that the transom was modified to accommodate a short shaft. I wonder why?  Seems like a lot of effort when they could have stuck with a long.  Also even if I built up straight across that red line, it only give me about 4" or 5" - but the difference is 7"

 

I am going to talk to a friend to see if he would be interested in helping me with this project. Otherwise, the motor is listed now and if anyone wants a decent long shaft, I will sell it for $950 at this point (at least that covers my gas and the cost of the motor). PM me if interested. 

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5 hours ago, siwash said:

thanks guys... seems like a bit of a project.. which begs the question - why not just sell it and buy a shorty?!  I guess the thought of changing the transom seems like overkill.  It's interesting that one or two of you pointed out that the transom was modified to accommodate a short shaft. I wonder why?  Seems like a lot of effort when they could have stuck with a long.  Also even if I built up straight across that red line, it only give me about 4" or 5" - but the difference is 7"

 

I am going to talk to a friend to see if he would be interested in helping me with this project. Otherwise, the motor is listed now and if anyone wants a decent long shaft, I will sell it for $950 at this point (at least that covers my gas and the cost of the motor). PM me if interested. 

Good choice, even rebuilding the transom , if the motor is an extra long shaft it would still be a mismatch though not as bad. Sailboaters use those , advertize where there is sailboat traffic

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1 hour ago, GYPSY400 said:

You'd be happier with a long shaft transom as I said before.. I own both and much prefer the extra 5 inches when reversing  or traveling down wind and coming to a troll from speed.   Newer Short shaft motors over 20hp are hard to come by.

Good points. I will think it over. I'm not the handiest guy so hopping my buddy can give me a hand. 
 

on a scale of 1 to 10 (10 being very difficult) where would you rank this project?

also is 5" enough? 

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I'd give this a 5 depending on your wood working abilities ( it's more wood working than mechanical)  I just measured my 16ft legend ( which is the same as a Starcraft or Smokercraft) and its 21" from the top of the transom to the bottom of the hull.  The motor has a 3/4" gap at the clamp ( dealer installed) and the motor is thru bolted with 2 bolts.

 Considering there are only about 2 good months of season left , you might want to make this a winter project and take your time.

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With all the great suggestions; the last I'm going to say on this matter is hang the frigging motor on the boat as is and go fishing!!!! Will It work 100% not likely but it'll get you on the water so you can enjoy yourself. Screw all the theory and just go fishing... Work out the bugs as you go!

Dan... 

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29 minutes ago, DanD said:

With all the great suggestions; the last I'm going to say on this matter is hang the frigging motor on the boat as is and go fishing!!!! Will It work 100% not likely but it'll get you on the water so you can enjoy yourself. Screw all the theory and just go fishing... Work out the bugs as you go!

Dan... 

I love that spirit and I would have taken it out but the thing is so long that I can't even put it on without it hitting bottom. I could adjust the angle so that it's higher off the ground but it's no where near ideal. Thanks for the input though. You're right - getting out there is the most important thing.  We overthink things sometimes! 

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