Best small petrol 4 stroke 3 or 4 h.p dingy outboard motors

[wingssail]

Originally Posted by Celestialsailor

Hi...This is where I found the 90lbs.

https://www.tohatsu.com/marine/int/outboards/M15D2.html

Ah Hah!

Mercury motor lesson of the day

Well, you see, that is a Merc made in the Japanese factory jointly owned by Mercury Marine and Tohatsu Corporation created in a joint venture called Tohatsu Marine Corporation (TMC) in 1987 to manufacture smaller outboards. Right now all Mercury models 30 horsepower and less are manufactured by TMC (since renamed) in Japan.

However Mercury continued to make small motors in the United States for many years and the 15hp model (6,8,9.9,10 & 15 which are all the same engine) continued the longest, even after they could not be sold in the US, because Mercury had an agreement with APBA which used the 15hp in Class A hydro racing (and still does in many places). My motor was manufactured in Fond du Lac, Wisconsin in 1998. It weighs 75 lbs.

Mercury currently has about 16 assembly sites around the world for their bigger motors but the basic design and foundry work occur in the expanded and upgraded factory in Fond du Lac, Wisconsin. The Verado V12 600hp motor is the latest to be developed there and is one of the most advanced engines in the world.

The small motors are basically commodities however the differences between the Tohatsu and Merc models reveal that Mercury still has a hand in the development of these motors.

My own ancient Mercury 15hp has been beat up and abused, including three times under the water, (twice while running) yet it is still fast, quiet, and reliable, and of course light. With the correct prop it will drive a light boat like my 77lb zodiac at 28 mph.

When we cruised around the world natives often gathered around in their canoes to watch me assemble my dingy. Before starting the Merc I would look around at them then point to the motor and say, "Mercury, number 1, made in the USA, one pull." Almost always it performed.

Now I am 76 years old. We'll see which one of us, me or the Mercury, quits first.

[Celestialsailor]

Originally Posted by wingssail

Ah Hah!

Mercury motor lesson of the day

Well, you see, that is a Merc made in the Japanese factory jointly owned by Mercury Marine and Tohatsu Corporation created in a joint venture called Tohatsu Marine Corporation (TMC) in 1987 to manufacture smaller outboards. Right now all Mercury models 30 horsepower and less are manufactured by TMC (since renamed) in Japan.

However Mercury continued to make small motors in the United States for many years and the 15hp model (6,8,9.9,10 & 15 which are all the same engine) continued the longest, even after they could not be sold in the US, because Mercury had an agreement with APBA which used the 15hp in Class A hydro racing (and still does in many places). My motor was manufactured in Fond du Lac, Wisconsin in 1998. It weighs 75 lbs.

Mercury currently has about 16 assembly sites around the world for their bigger motors but the basic design and foundry work occur in the expanded and upgraded factory in Fond du Lac, Wisconsin. The Verado V12 600hp motor is the latest to be developed there and is one of the most advanced engines in the world.

The small motors are basically commodities however the differences between the Tohatsu and Merc models reveal that Mercury still has a hand in the development of these motors.

My own ancient Mercury 15hp has been beat up and abused, including three times under the water, (twice while running) yet it is still fast, quiet, and reliable, and of course light. With the correct prop it will drive a light boat like my 77lb zodiac at 28 mph.

When we cruised around the world natives often gathered around in their canoes to watch me assemble my dingy. Before starting the Merc I would look around at them then point to the motor and say, "Mercury, number 1, made in the USA, one pull." Almost always it performed.

Now I am 76 years old. We'll see which one of us, me or the Mercury, quits first.

Great story...I feel educated!

[rslifkin]

For 4 stroke outboards, if you want anything bigger than a 10hp, you're looking at north of 90 lbs. I think the lightest 15s are in the 95 lb range. However, the Tohatsu 9.8 4 stroke is ~82 lbs, so if it's enough power, that's a more manageable weight.

That said, I went with a 6hp (4 stroke, 57 lbs) specifically to keep weight down (particularly being that I'm lifting the dinghy in davits with the motor still mounted). It's not fast, but the aluminum skiff we carry as a dinghy is fairly easily driven, so it's enough power to plane. I'm still working on getting the whole setup dialed in, but it's good for 13 - 14 kts with 1 person (might see 15 if I determine it can handle more prop pitch, as it's underpropped with 1 person and will kiss the rev limiter if you stay at WOT). Haven't gotten a good top speed run with both of us yet, but I expect to see 12 kts.

In our use case, we're unlikely to have to make a long distance run with both of us, the dog, and a bunch of stuff, so ability to plane at high speed with a full load isn't particularly important. Speed is more for exploring. Plus, there's a limit to how fast I can run this dinghy in any kind of chop before the ride becomes too harsh, and it's a dry ride even without flying along at light speed. I've yet to run it in conditions where I've gotten splashed.

[Mike OReilly]

Late to this party since I’m actually off cruising (first time in over 2years). I still have the 10’ portabote. Still using the 3.5 hp 4-stroke. Still very happy. All manageable without the need for cranes or winches or bridles.

[Celestialsailor]

Originally Posted by Mike OReilly

Late to this party since I’m actually off cruising (first time in over 2years). I still have the 10’ portabote. Still using the 3.5 hp 4-stroke. Still very happy. All manageable without the need for cranes or winches or bridles.

…and davits.

[purvisgs]

The old Tohatsu 3.5 2-stroke (Nissan 3.5, Mercury & Johnson 3.3) is of course a crowd favorite at 27lbs, but the smallest Suzuki 2hp (&2.2hp, also 2hp Yamaha) 2-strokes are good too and even lighter starting around 22lb

Running out of gas before storage is one step, but the more important step is a heavy dose of fuel stabilizer in the gas, sta-bil in the states. I’ve NEVER had carb issues in any of these small 2 & 4 strokes that everyone else thinks are so unreliable. I add an additional inline fuel filter as well in the line, if external tank.

Now to the question about four strokes- Suzuki 2.5 is the best, based on weight. The next step up is the Suzuki 6hp (55lb) as bonus has connector for external tank. The tohatsu/merc 6 (4,5hp same, 60lb) gets a bad reputation as a shaker, but I personally have had great luck with them. The Tohatsu 3.5 might be worth consideration, and also the tohatsu propane option, but nothing special weight wise around 40 lbs so for these. so unless your dinghy is 3.5hp max then a 6hp is worth strong consideration.

I haven’t had good luck with the Honda 2hp personally, and don’t like the clutch, but some people like them, they’re about same weight as the Suzuki, and there is the argument to be made that being air cooled they are a great option for a dinghy motor that you know will be rarely if ever flushed in fresh water after use.

[Celestialsailor]

I really think I might try the 2 strokes, this next time. I had a Tohatsu 6hp 4 stroke which, with a crane on the stern rail was a breeze to bring up. But when getting it up and then running the gantlet to the companionway steps and store it below at 57lbs. I have a 8ft. Porta-Bote and they recommend a 35lbs. outboard. I think I could squeak a Nissan 5hp. 2 stroke on the transom at 42lbs. The Tohasu 3.5hp. 4 stroke is 41lbs. I haven't found a Tohatsu 3.5hp., under $750 whereas the Nissan 5hp., go for around $400-$450...hefty difference.