Which Outboard

[Tortuga's Lie]

In my experience with the dinks outboard, I think it's a bit of a trade-off. I have had a 2hp Evinrude 2-stroke, about 25 pounds: hard to start since I wasn't running it except for weekends, light, relatively loud, easy to fix.
I replaced it with a 2.5 Yamaha 4-stroke, about 30 pounds. Starts right away, just a little heavier, not as quiet as I thought it would be, but the main difference that I wouldn't do without now is the neutral. My old Evinrude stayed in gear.
I don't think the fuel efficiency enters in the picture, much.

[seahag]

I have two mercury two strokes that are old, have thousands of hours, and start every time. Run great- I have watched my friend pull on his yamaha starter cord until he was blue in the face many tomes. Choice is clear to me!

[cfarrar]

I like the 4-strokes: quiet and smooth, but you've got to be meticulous about clean fuel. If you put it away for the winter, it's all too easy for gasoline left in the carb to foul the jets, even when using a fuel preservative.

[Tortuga's Lie]

Originally Posted by seahag

I have two mercury two strokes that are old, have thousands of hours, and start every time. Run great- I have watched my friend pull on his yamaha starter cord until he was blue in the face many tomes. Choice is clear to me!

Quite the opposite with my two engines, I guess the difference is the usage: two strokes need to be used more frequently. I have a 17ft center console with a 125 mercury 2 stroke and it needs to be run or else the carburetor gets fouled, same thing with the dinks Evinrude 2-stroke.

[Sailor Doug]

I have a 5 year old Yamaha 4 HP. I am not very impressed with engineering. Tip top grip is missing tip locking is poor. Requires special tool to remove plug, finding which bolt to take out to change oil is not simple. I had a lot of starting problems. I now put in fuel stabilizer and always close the tank vent and now starts well but idle is poor. Not a typical Japanese engineering. I would not buy another Yamaha I was very disappointed.
A two stroke uses 35% more fuel and you have to carry it to.

[jeremiason]

You didn't say where you where or what you are using the dinghy engine for?

If you are a fulltime cruiser going to second or thrid world countries, the Yamaha 4-Stroke by far is the most reliable and Yamaha has parts availabilty where ever you go.

Someone said fuel economy doesn't matter... I disagree, especially when you get about 35% better fuel milage with a 4-Stroke over a 2-Stroke, which can either reduce the size of your fuel tank or extend the distance of your trip.

Some else mentioned power from a 4-Stroke verses a 2-Stroke. Top end speed of both engines has less to do with 2 or 4 stroke and more to do with gear box ratio and the prop pitch. The more prop pitch, the more top end speed... Or less pitch for more power out of the hole.

[jeremiason]

Originally Posted by cfarrar

I like the 4-strokes: quiet and smooth, but you've got to be meticulous about clean fuel. If you put it away for the winter, it's all too easy for gasoline left in the carb to foul the jets, even when using a fuel preservative.

We had that problem once with our Yamaha 15 HP 4-Stroke when we first purchase it. We stored the engine for 3 months without running the engine dry. We had to rebuild the carburetor.

Over the last four years we have gotten in the habit of using fuel stabilizer and running the engine dry of fuel when we are storing it.

No problems since then.

.

[Sailor Doug]

I don't know about all Yamaha motors but as a engineer I can tell you what is wrong with the 4hp. This motor seldom goes 4 days without use for 5 months a year and is very well marinated. You a right about needing parts.

Two stroke and four stroke have a very different operating characteristics because of the large difference in operating rpm.

[charliehows]

You'll get tired of not being able to push it up onto the plane, try and find a bit more hp if i was you, i got a small 2 str recently and its great but for the little bit more money i should have got something a bit more powerful...on the other hand its a one hand job to hoist it around which is good (yeah yeah he said 'handjob' funny)

[Sailor Doug]

You are right about speed it will be a 15 or 9.9 four stroke spring. I' m a senior but not that old.

[Cheechako]

A 5hp Merc will get an 9ft inflatable floor boat up on a plane. I'd go with the 2 stroke either way.

[Sailor Doug]

4 HP 4 stroke will get by 3.5 meter one plane, but it is rated for 15 HP.

[ranger58sb]

Our 46-lb 5-hp 2-stroke won't get our 3.1m (10'2") RIB -- 135-lb boat, rated for min 10 max 15 hp, even with only one pax (me, 190-lbs) -- on plane.

I wonder if my idea of "planing" is off; our motor will raise the bow in the air... but we're still plowing through the water...

-Chris

[Ruffriders]

Another option has come up, an 11' caribe rib with a 15hp Suzuki 2 stroke, 2 years old only about 15hours
MORE MONEY!

Thoughts,

[Sailor Doug]

I had a 3 meter rib with the same 4 HP 4 stroke and it would not plane. I bought a soft bottom 3.5 meter with a aluminum floor. Same motor planes at 7.2 knots (gps). The difference is the transom is about 6" further forward from the rear tube.