13-footer: Auxiliary Engines

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
socal_2367
Posts: 1
Joined: Mon May 15, 2017 3:29 pm

13-footer: Auxiliary Engines

Postby socal_2367 » Mon May 15, 2017 3:59 pm

Hi. I have a 1975 13-footer with stencil number 2B5641 and HIN BWCB3647_751, and a late model E-TEC 40-HP outboard.

What experience do owners [of 13-foot Boston Whaler boats] have with auxiliary outboard engines?

I [do not want] to permanently mount a kicker or auxiliary engine on the transom. Rather, [I want to] know if it is possible to hang one over the transom adjacent to the main motor for backup. I had thought of perhaps installing a bracket, but--aside from the fact it is a smaller boat--I am concerned about putting any holes in the transom, especially in areas where there may not be any embedded plywood.

I believe the outboard clamp width would have to be 2.25-inch-wide.

Other considerations and any feedback greatly appreciated.

Thank You

goldstem
Posts: 65
Joined: Thu Oct 29, 2015 12:57 pm

Re: 13-footer: Auxiliary Engines

Postby goldstem » Tue May 16, 2017 11:57 am

The classic 13--after 1972--had an indentation on the port side of the transom to take a small auxiliary. [A small auxiliary engine can] clamp right to the hull. The lighter the better. One of the old Nissan or Tohatsu 2.5 or 3.5-HP two-stroke-power-cycle outboard engines that weigh about 30-lbs would work well.

jimh
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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: 13-footer: Auxiliary Engines

Postby jimh » Sun May 21, 2017 1:26 pm

What is the motivation to have an auxiliary engine on a 13-footer?

Are you interested in being able to achieve very slow trolling speeds?

Or, are you interested in having a back-up engine?

A modern outboard engine like an E-TEC will idle down and run all day at 500-RPM, burning gasoline in the most economically possible manner. I would expect that the E-TEC would consume less fuel than an older classic carburetor 3.5-HP engine. Older carburetor outboard engines would also generate more exhaust gas pollution and emissions. They also would likely need to use pre-mixed fuel, and would need a separate fuel tank to draw from. I don't see exactly what advantage is gained by bringing that old technology to the transom of a 13-footer, nor how any advantage could overcome the added weight and awkwardness of having two engines on the transom of such a small boat.

As for having a back-up engine on a 13-footer: where do you plan to operate the boat? Usually a 13-footer is used on inland or protected water. It's not like you are going to be 40-miles offshore and have the E-TEC quit.

moments
Posts: 2
Joined: Thu Feb 18, 2016 10:18 pm

Re: 13-footer: Auxiliary Engines

Postby moments » Sat Jun 10, 2017 12:32 pm

I sometimes mount an early 1980's 6hp Johnson (short shaft) on the transom when I go any distance greater than 15 miles out of the harbor. Its not a problem and will push the boat at about 5.5 mph ... a good trolling speed, or back home in a few hrs if needed. I just move the fuel tanks a little to balance the load if needed.