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Author Topic:   Honda 50 & the 15"-20" transom issue (13')
Highwater posted 09-24-2001 12:30 AM ET (US)   Profile for Highwater  
I have a 1972 13' "Sourpuss" Whaler with a 1987 40 hp Johnson. Where the engine attaches, the transom is 16.5" in height, although I imagine that I have what is commonly referred to as a 15" transom (is that right? Are all 15" transoms actually 16.5 inches?). The Johnson has a 20" shaft but instead of filling in the transom notch or using a Jack plate, the previous owner just bolted the outboard to the transom as if he were hanging it on a 20" transom. Consequently, it is not hanging on anything--it is entirely supported by the four through-transom bolts. There is 3.25 inches of air between where the motor should be hanging on something and the top of the transom.

Anyway, the Johnson runs fine but I have determined that I want to re-power with a Honda outboard. I know that Hondas are twice the price of the competition and are heavy and may not run quite as fast or get quite as good of fuel consumption as some others, but I love how quite and smooth they run at any speed. I dream of owning one.

And I have found a reasonably-priced, four-year-old, 50 hp Honda with power tilt and trim. Even though the 13' is rated for just 40 hp, I thought that this would be a good fit since the 40 hp Honda and the 50 hp Honda weigh the same--203 pounds. I like the idea of having a 50 hp engine and running it at a lower RPM than I would a 40 hp engine.

But there is no way that I am going to hang the engine on air the way the previous owner did with the 40 hp Johnson. So I either need to fill in the transom notch or use some kind of Jack plate.

Does anyone have experience filling in the transom notch so as bring the pre-1973 13' transom up to 20"? Could a novice like me do it? I am sure that it would be expensive to have a boatyard do it.

The Jack plate idea concerns me because my 13' already seems back-heavy and most Jack plates come with a 4" setback. If I set the 203-pound engine back four inches it might be the same as adding a lot more weight to the back of the boat.

From previous posts on a related thread, I understand that the Cook Manufacturing Company ( sells a 5" vertical extension with no setback. But it looks very thin and I do not understand how I would rest my engine on it.

Another alternative would be to sell my boat "as is" and search for a post-1972 13' that already has a 20" transom. Or maybe I should move up and get a 15' with no engine and put the 50 hp Honda on it. There is a 15' for sale in Florida right now with no motor or trailer for $1400. I could sell my 13, buy the Honda engine and the 15 with no engine, and come out about even. Of course my 13 is gorgeous and the 15 needs some fiberglass repair and wood work.

I like the fact that the 15--with its different hull design--handles the waves better than a 13. But I am hesitant to go from a boat that is rated for 6 people to a boat that is rated for 5 people. And the fact that the 15 is more "weight sensitive" concerns me because I have two young daughters, ages 4 and 7, who like to walk around the boat while we are under way.

The 17 Montauk is a gorgeous boat but I would want a Honda 90 to go with it and I would end up spending $10,000 or more, which is twice as much as what I have in mind with a 13 or a 15.

I apologize for posting such a long series of questions but I need to make a decision soon and I respect the opinions of the members of this group. Thank you.

russellbailey posted 09-24-2001 10:14 AM ET (US)     Profile for russellbailey  Send Email to russellbailey     
Our 1980 15' Striper (same hull as Sport) is rated for 7 people on the original BW info plate on the hull. I've heard others before say the 15 is only rated for 5 people, so maybe BW revised the rating. 7 in a 15 is a lot of weight but we did it a lot when I was in high school (skiing with friends).

I don't have any other answers to your questions, but I would not worry about a 15 being less capable of handling a load than the 13.

Bigshot posted 09-24-2001 11:23 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Once you drive a 15' you will never get into a 13' again. Do the swap, if not, where is that 15 in FL?
Highwater posted 09-24-2001 11:42 AM ET (US)     Profile for Highwater    
I am glad to hear that some (all?) 15's are rated for 7 people as our daughters like to bring along friends and I like to have everything as legal as possible. I got the "5 person rating" from the Reference section of this excellent web site (

A light-weight, short-shaft, 30 hp Honda would be a good option for some people but I need at least 40 hp for my loaded boat to get me up with one ski. We love to ski and we always seem to have a full boat. I can slalom with my 40 hp Johnson, but it takes 15-20 seconds for the boat to get me up and less-experienced skiers can not hold the slalom ski straight under the strain for that amount of time. A 50 hp would be perfect if it were not so heavy and if I had the transom issue solved.

I know that the 50 hp Honda weighs 203 pounds but I have no idea how much my 1987 40 hp Johnson weighs. I assume that they are about the same or that the Honda may be slightly heavier. Does anyone know how I might find this out?

I am leaning toward selling the 13 and getting a 15 with no motor that I can power as I wish (it will either be the Honda 50 or the much-heavier and slightly-over-legal-horsepower Honda 75).

JFM posted 09-24-2001 12:19 PM ET (US)     Profile for JFM  Send Email to JFM     
On the 15vs20 transom issue. On my '72 13' sport. I made a patern of the cut out and used a piece of 1" teak and cut it on a band saw to fit in place. I clamped it in with 5200. I then made a 3/4" by 3/4" piece of teak to mout forward of the larger transom piece and screwed and 5200 in from the top. I then screwed the transom piece into the 3/4 piece to secure. I now feel comfortable with the 20' Evinrude 40hp on it. Regards, Jay
Highwater posted 09-24-2001 12:37 PM ET (US)     Profile for Highwater    
JFM, did you raise the transom a full five inches or 3-and-a-quarter inches? Mine only seems to need to be raised 3.25 inches (????). Also, my transom is curved slightly outward (aren't they all?) so any type of cutout would also have to be curved. Did you bend the teak to make the curve?

Eric Cook of Cook Manufacturing ( wrote to me to say that his company's vertical extension, which measures 20 1/2 x 5 1/2, was a good way to mount the Honda with no setback. But I still cannot visualize how that would look.

If all of the pre-1973 transom notches on 13' Whalers have the same dimensions (????), it seems that someone would make a fiberglass insert that could be put in that space and held there with something like Cook's vertical extension.

bigz posted 09-24-2001 12:51 PM ET (US)     Profile for bigz    

For what it's worth go with the Cook riser. You avoid possible failure depending on how the filler and reinforcement was accomplished. Remember only plywood is in the immediate motor mount area nothing on either side.

You will hardly notice the Cook bracket. If for some reason you want to sell her easy for new owner to convert back to the original.

Just a few thoughts --

JFM posted 09-24-2001 01:48 PM ET (US)     Profile for JFM  Send Email to JFM     
Highwater, I raised the transom to flush. To compisate for the curve I cut, grinded and sanded the teak to match. I also made a thin plexiglass mount to go between the motor and the transom. Keep in mind I have a complete commercial wood shop at my father-in-laws plant. Regards, Jay
JFM posted 09-24-2001 01:53 PM ET (US)     Profile for JFM  Send Email to JFM     
Highwater, I would have to agree to go with bigz's recomendation. Regards, Jay
Highwater posted 09-24-2001 05:14 PM ET (US)     Profile for Highwater    

You are doing a good job convincing me that a 15' would be better boat than the 13. Assuming that my boating needs consisted of river exploration with a family of four, transporting camping gear in addition to four people, and water sking, would you say that the 16/17 would be an even better fit than the 15? Or are you just partial to the 15?



Bigshot posted 09-25-2001 09:37 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
I have had 3 13's,15's and 17's. I think the 15 has the most smiles per hour than any of them. It tows great, easy to get in, will run faster than a 13 if both had 50's just due to hull design. Rides like a caddy compared to a 13 and has better resale. 1 test ride and you will see. Stay with the 15 for a while, then go to a 17 if you want. 15's are the woo.
Highwater posted 09-25-2001 11:28 AM ET (US)     Profile for Highwater    
Thanks, Bigshot. You make a strong case for the 15' . I already have an 11' Whaler and a 13' , and this weekend I am going to look at a 15' and two 16/17 models (one a 1965 and one a 1979). My wife is under the illusion that I will settle on one boat and sell the others. That is going to be difficult emotionally, although I will need to do it financially. It is a lot easier to buy these beautiful boats than it is to make the decision to sell them.
Bigshot posted 09-25-2001 01:40 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
The difference you see between the 11 & 13 will be the same if not more between the 13 & 15. Good luck!

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