CONTINUOUSWAVE

Q1: what outboard engine in the 30-HP to 40-HP range is recommended for a 1973 13-footer?

BACKSTORY
I had a 13-footer when I was 10-years-old. It provided some of my best memories. I’m now 51 and just bought a 1973 13-footer (my birth year). It needs to be re-powered and new controls, but it is a good clean boat.

You are in luck with a 1973 13-footer because that model year should have a transom height of 20-inches, instead of the 15-inch-high transom used in older models. But you are right at the epoch when the transom height changed, so you should look carefully at the boat to see if the transom has a notch or cut-down area that indicates it needs a 15-inch shaft outboard--which is hard to find. But if you have the 20-inch transom, then you can have your choice of many outboard engines in the 30 to 40-HP range.

It is common for the exact year of production of old Boston Whaler boats to become a bit confused over the years, and you cannot rely on what a state registration indicates was the actual model year or year of production.

See more about the 13-footer at

https://continuouswave.com/whaler/reference/13/

As for choice of engine brand, I would first check out the various outboard engine dealers in your area. See what dealer you like doing business with. These days many dealers hardly ever sell a loose outboard engine and rig it on an old boat. The outboard engines they sell are already rigged on new boats at the boat builder. You want a dealer that has experience with old boats and putting on them new engines.

Also, you are going to be very surprised to find out the price of a new 40-HP engine—about $4,000 or higer—and how much added costs the new controls and other rigging components will be, and the labor to install and rig the engine. Get a firm quoted price estimate for the engine, the installation, and all the accessories, like a fuel tank and a propeller.

And be concerned about the engine weight. Some modern four-stroke-power-cycle engines with electric starting and power trim (and the battery they will need to run) will weight a lot more than a c.1973 two-stroke-power-cycle pull-start engine that would have been typically used on a 13-footer back then. Avoid too much engine weight. The transom on a 51-year-old boat does not get stronger with age.

Many smaller four-stroke-power-cycle engines sold under Brunswick's Mercury brand are actually made by Tohatsu in Japan. So do not shy away from Tohatsu--they make excellent engines.

Tohatsu MFS30D is probably the best modern engine in terms of weight. See more at

https://www.tohatsu.com/marine/na/outboards/mfs30d.html

It is available in both 15-inch and 20-inch shaft length, and can be rigged for tiller steering or remote steering.

Or, revive whatever older engine is already on the boat. Some classic two-stroke-power-cycle engines from the 1970’s could run forever.

That’s extremely helpful. I went to my local outboard dealer today and the 40-HP engine was $6,000, plus controls, propeller, and fitting it all, and with tax was close to $8,500! Yikes !

Myzippy wrote:I went to my local outboard dealer today and the 40-HP engine was $6,000, plus controls, propeller, and fitting it all, and with tax was close to $8,500!

Even for today's inflated prices, it sound like that dealer really does not want to sell you an engine and install it on your 50-year-old boat. That seems very high. Find a dealer who is hungry, who has the engine in stock and hasn't been able to sell if for two years.

Installing a 40-HP engine is not particularly difficult, and you could probably do it all yourself. The only catch is the engine warranty. Typically the engine manufacturer will not provide a warranty for the engine if the engine is not installed by a certified and authorized dealer of that brand.

Which brand were your pricing? I would guess Yamaha. Find a Tohatsu dealer. The price for the engine should be about $4,000.

If you also need new remote control steering, new remote control engine shift and throttle controls, new engine remote wiring harness, new ignition key switch and safety lanyard, and basic engine gauges like tachometer and alarm warning indicators, that is going to very quickly add up to a considerable amount of money and labor, if you hire the labor.

The propeller for a 30 or 40-HP outboard can be aluminum and should not cost more than about $100 to $125.

As I mentioned before, if there is an older two-stroke-power-cycle engine on the transom of the 13-footer now, you should consider rehabilitating that engine. Typically those engines are very simple, and when you have them in good condition and properly tuned, they start easily and run forever.

I just purchased a new Yamaha 30-HP engine for $5,600. I looked and called nationally, but I could not find [an offer that was] much better. [The total cost of the re-power will be] $7,000 [and will include a] propeller, [remote engine] controls,[necessary] cables, sales tax, and [installation labor]. A five-year warranty [will be provided] and all will be fitted correctly.

A fun Summer is ahead.

Choosing a top brand is always a good decision, even though it may initially cost more. Yamaha outboard engines have a very good reputation.

In 2023 I re-powered a 1981 SPORT13 with a Tohatsu 30-HP—an excellent engine. The new 30-HP is about 30-lbs lighter than the previous version, and it shows. The all-in cost to re-power was about $7,200 here near Boston.

I replaced the Johnson 30-HP engine that was original to a 1988 SPORT 13 with a HONDA BF25 .The Johnson failed at the beginning of the 2024 season, and my marina had the long-shaft Honda in stock. Many like [to have] more [horse]power, but for our use of the SPORT 13 [the HONDA BF25 engine] is just fine. With a tailwind, two good-sized adults, and all our gear the top boat speed is 27-MPH. That's faster than I need to go. Even going against the tide I'm happy.

The marina mounted [the HONDA BF25 engine] and I rigged the electrical cables and the remote controls. The cost was $5,500. I didn't want to delay getting the boat back in the water, and I didn't shop around. I had no desire to buy on-line and get no support if needed.

When I restored my 1982 SPORT [13] about nine years ago [c.2017] I re-powered with a Mercury 40-HP FourStroke EFI, including a four-bladed propeller, new steering gear, and some other stuff. That cost a bit over $7,000, with the engine parts taking up about $6,300. I changed the fuel tank to a 14-gallon on-deck tank mounted under the front thwart seat to balance out the engine weight.

Since the boat is operated at over 8,000-feet-above-sea-level elevation. I rigged an 11-pitch four-bladed propeller. I might have been able to get by with a 13-pitch, as the 11-pitch can get the boat onto plane in about two boat lengths [26-feet]. I chose the four-blade to lift the stern since the engine is heavier than the original.

If I were to move the boat down to 600-feet-above-sea level I would need to change to a different propeller [because the engine will be able to produce more power].