16" Transom With 20" Shaft

[CJF]

Hello,<br /><br />I want to mount a 1966 18hp evenrude long shaft on a 12' Alum. with a 16" transom. The motor is a long shaft. The boat is rated for a 15hp. J.B indicated that this motor is a 14 to 15hp by todays standards. Will this give me problems?<br /><br />Chris

 

[roscoe]

Re: 16" Transom With 20" Shaft

It will work ok on a boat that size. Go for it. <br />Could get a little wild with that much power, just take it easy till you find out how it handles.

 

[JB]

Re: 16" Transom With 20" Shaft

Well, I don't think I agree with Roscoe.<br /><br />That engine should make your little boat scat like the devil. An extra 5" of foot hanging down in the water would make her handle pretty squirrely in my opinion.<br /><br />I think you should raise your transom 5". I would do it by bolting a pressure treated or laminated (2 layers of 3/4" Marine grade plywood) 2"X12" to the outside your transom to stick up 5" above the present level, and mount the engine to that so that the AV plate is level with the keel.<br /><br />Good luck.

 

[biloxiriver]

Re: 16" Transom With 20" Shaft

That must be a wide 12' aluminum boat to be rated for a 15hp motor!! Here is a web address that gives info for calculating hp ratings: http://members.aol.com/spinners/hp.html <br /><br />I just mounted a longshaft 35 on a short transom to do it I bought a transom jackplate for around $100 (you can get it online a little cheaper; I just like to use my local marine suppliers if they are not too far out of whack on their price). The good thing about doing it this way is the unit is made for that purpose and by the time you spend the material costs and labor to build your own out of wood it is worth it. Here is the web address http://www.thmarine.com/product.cfm?PRID=23. Now the drawback: with this type of plate the engine is setback 4". Good luck.