Custom outboard: 15-40hp w/25"+ Shaft?

[Mr Efficiency]

I know of 70 horse Johnnos were being extended by cutting the shaft, and welding in the extra length, but as you say metallurgy is a concern. Maybe there was enough spare capacity in those shaft diameters to absorb a loss, I'd guess if the driveshaft is a bit marginal to start with, it is problematical.

[Matt Gent]

http://www.marineparts.com/partspage...ories/acc8.htm

http://www.baymfg.com/

[salukikev]

Thanks! I'll definitely follow up with these guys! I had seen that 1st link previously, but not the 2nd. I think its interesting that I haven't been able to find a motor that has been retrofitted with one of these kits so far, and yet there is a large selection of conversion kits available. I guess my new question is what motor has the highest power/weight ratio in that range- then I will just add a kit to whatever that answer is.

[frank smith]

There is a kit for extending Tohatsu 25hp to 25" . This is the same engine as the Mercury and Mariner 25Hp .

[liki]

Atleast old OMC 2-cyl outboards had a 5" extension kit available. See e.g. here: http://www.evinrudeonlineparts.com/p...f28299%2f41281

I have a 1984 short-shaft 35hp that I fitted with leg from a 1994 20hp model. There are some very subtle differences like different size screws and maybe you'll one half of the gear shart connector from the engine and the other half from the leg, but if you are able to find an extension kit still from somewhere it should fit all 2-cyl 2-stroke for about between 1996-1986 for 20/25hp and 1996-1980 for 30/35hp. Browse the BRP parts catalogue, but the only source for the kit is likely ebay nowadays.

EDIT; hmm. And check also the products from these guys: http://www.baymfg.com/ - Could prove to be much easier that way.

[frank smith]

Originally Posted by frank smith

There is a kit for extending Tohatsu 25hp to 25" . This is the same engine as the Mercury and Mariner 25Hp .

this is easily gotten as it is a Mercury part , and will work for merc ,mariner, and tohatsu
http://www.boats.net/images/diagrams...MMON//5764.png