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Choosing a 2.5HP outboard

A comparison of the smallest outboard engines for your small sailboat or tender

MacGregor 25 on Lac St-Louis
MacGregor 25 on Lac St-Louis

The latest models of the 2.5HP outboards are the tiniest you can get. They’re the least expensive gasoline outboard you can buy. They’re light enough to carry in one hand. They’re simple enough to maintain and do most repairs with common tools. And from their bigger siblings they get hand-me-downs for quality, reliability, efficiency, and power.

They’re not as tiny in capability as you might guess. When he had his 17-foot Edel 540, my father put a Yamaha 2.5HP on the transom. A Honda BF2.3 pushes my 19-foot O’Day Mariner. Both boats displace over 1000lbs and both outboards kept boot stripes above the water and hum along at 3-4 knots at half-throttle.

2.5HP outboards share other similarities:

Still, each offers its own trade-offs. I’ve ranked them according to their manufacturers’ specs only. Which machine you choose depends on your specific needs.

The winner

Suzuki DF2.5

Suzuki DF2.5

Shaft length (inches): 15, 20

Weight (lbs/kg): 15-inch: 29/13.2, 20-inch: 31/14.1

Cooling: water

Tank capacity (US gal/litres): 0.26/1

Carrying handles: front and rear

Transmission: forward and neutral

Warranty (years): 3

From specs alone the Suzuki mostly beats the rest. It’s as light as the Honda, but with real shifting and the quietness of water cooling.

The Suzuki has a full-on handle on the rear. It’s great for carrying the outboard. It’s also useful as a complement to the tiller when reversing.

A close 2nd

Yamaha 2.5HP

Yamaha 2.5HP

Shaft length (inches): 15, 20

Weight (lbs/kg): 15-inch: 15-inch: 37/16.8, 20-inch: 40/18.1

Cooling: water

Tank capacity (US gal/litres): 0.25/0.9

Carrying handles: front and rear

Transmission: forward and neutral

Warranty (years): 3

My father had one. It started quickly, ran smoothly, and was just as cheap on fuel as my Honda. The Yamaha is heavier, but comes with a real shifter and runs quieter because of its water cooling. It has a rear handle, like the Suzuki.

The Yamaha simplifies storage and transportation. There’s no requirement to keep the engine upright or lying on a specific side to prevent oil leaking.

Runner up

Honda BF2.3

Honda BF2.3

Shaft length (inches): 15, 20

Weight (lbs/kg): 15-inch: 29.5/13.4, 20-inch: 31/14.1

Cooling: air

Tank capacity (US gal/litres): 0.29/1.1

Carrying handles: front

Transmission: forward clutch

Warranty (years): 5

I have one so I have the most to say about it. Generally, it’s a great outboard. It starts quickly, runs smoothly, and sips fuel.

The automatic clutch is less hit and more miss. At idle it’s in neutral. Turn the throttle and the clutch engages forward. It works well enough, but combining throttle and shifting can be frustrating. The practical way to get to neutral is to turn the throttle down all the way. That means vigilant maintenance to make sure that the throttle stop is properly adjusted and the engine won’t stall at idle.

Also, starting the engine guarantees an immediate burst of thrust while I fuss with the choke and throttle to get down to idle/neutral. That’s inconvenient at the dock but a bigger pain in the ass when I’m raising anchor.

The Honda uses air cooling. That saves weight. No water pump means less maintenance and no impeller burning out if (who’s kidding who—when) the foot leaves the water. But the engine is noisier.

Close but not quite

Tohatsu MF2.5 and Mercury 2.5

Tohatsu MF2.5

Shaft length (inches): 15

Weight (lbs/kg): 41/18.4

Cooling: water

Tank capacity (US gal/litres): 0.26/1

Carrying handles: no

Transmission: forward and neutral

Warranty (years): 5

I lump the Tohatsu and Mercury together because of their closeness in specs, probably from their corporate closeness. I’ve never used either one. Do you have one? Let me know.

They’re the heaviest and are only available in 15 inches.

Tohatsu and Mercury also offer a 3.5HP. This outboard shares the same specs as their respective 2.5HP outboards but also come in a 20-inch model.

Mercury 2.5

Shaft length (inches): 15

Weight (lbs/kg): 41/18.4

Cooling: water

Tank capacity (US gal/litres): 0.3/1.1

Carrying handle: front

Transmission: forward and neutral

Warranty (years): 3

The Mercury has a larger fuel tank. Keep in mind we’re talking about an extra quarter cup. Curiously, Mercury offers a 3 year warranty instead of Tohatsu’s 5 years.

Related articles

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A comparison of 4HP outboard engines for your small sailboat or tender

Choosing a 5/6HP outboard


A comparison of 5HP and 6HP outboard engines for your small sailboat or tender

At your service

Humbly yours,

Marc
Supreme Purser