Matching boat with motor…..

[amuller]

Now that winter has finally arrived (late) in Minnesota, boats and motors put away, thinking about next spring:

I have an 11 1/2 foot tin boat weighing about 100 pounds. Got this as I can cartop it on our van with reasonable effort,and so take it with our tent trailer…

I fixed up a ’62 Johnson 5.5 for this hull. But,while it starts and runs nicely is has no power to speak of. It can’t begin to plane this boat with the two of us in it. It would be fine for fishing on a small lake, but I want to be able to run up the river and need more speed. So my question is: how much power do I need? Would a 7.5 or 10 make a big difference?

I have two 12 hp Elgin/West Bends that will run. These might be pushing the limit for power on this hull but they are supposed to be good motors, and not very much heavier than the 5 1/2. i also have a 7.5 hp Elgin that’s the same basic motor with a smaller engine under the hood.

Thoughts? Suggestions?

[garry-in-michigan]

The late ’50s early ’60s ten horse OMC outboards do a great job on a boat like that. If it’s only you and some fishing tackle the 7-1/2 horse will do. The super ten Mercury puts out around 15 horse power and could be dangerous on a boat that light. Same for the 15 horse power Evinrude Super Fastwin from the mid ’50s. . . 🙂

[frankr]

Any chance one of your Elgins have the key-selectable horsepower feature?

[eviltwin]

What does the Coast Guard tag on the transom say for horsepower?

[amuller]

quote FrankR:

Any chance one of your Elgins have the key-selectable horsepower feature?

No. I’ve heard of it, but never seen one.

[amuller]

quote EvilTwin:

What does the Coast Guard tag on the transom say for horsepower?

No tag. Long gone. Horsepower ratings for hulls of that type and sizesize seem to range from about 7 1/2 to 12 or so.

[crosbyman]

a 10hp QD is a heavy engine & with you in the back I would worry about a nice flip over if you don’t have a buddy in front …even a small one will help !

wear your PFD 😯

Joining AOMCI has priviledges 🙂

[sydinnj]

With no tag the rule of thumb for safe weight in the boat, which includes motor, gear and people is length X width divided by 15 X 150.

My old miro craft is a 12 ft and I did 19.6 with my daughters Merc KE-4, actually it was scary at that speed. It was dancing up on plane. Now I think about it we had the same motor on my friends 14ft row boat and it did well with two of us.
I actually have acouple of these motors that I would sell or trade if anyone is looking for one.

[amuller]

Using the length x transom width formula from the Code of Federal Regulations gives a max hp of ten. Not sure if transom strength is a reducing factor on these little boats. Anybody know?

Am sure I would not run the boat alone without at least a tiller extension and/or ballast in the bow.

I plan to try the Elgin/West Bend 12s in the spring.

[westwind]

7.5HP is probably the sweet spot for that boat. I had a Feather Craft Cartopper and played around with different motors. 10HP is better with two people in the boat. They tend to be pretty sensitive to small changes. If it’s just you in the boat with a 12HP, watch the freeboard at the transom. It’s easy to swamp the boat by leaning back to check or adjust something on the motor. They do scoot right along with the right combination though. Here’s a picture of one of mine with a 7.5 Scott.

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