Mercury 3.5 HP Outboard Junk?

[Bash]

Originally Posted by Tellie

I've got maybe 200 hrs on this engine and I've stripped the carb down four times already.

My first outboard was a 1950's Mercury 10hp "Screaming Mimi." It was a direct drive with no neutral, if you wanted to stop you turned it off. The carb in that thing had to be rebuilt once a month.

Maybe your rate of one rebuild every 50 hours of operation is progress for Mercury?

[IdoraKeeper]

Originally Posted by Bash

My first outboard was a 1950's Mercury 10hp "Screaming Mimi." It was a direct drive with no neutral, if you wanted to stop you turned it off. The carb in that thing had to be rebuilt once a month.

Maybe your rate of one rebuild every 50 hours of operation is progress for Mercury?

Had one of those when I was a kid...put on tuned exhaust and race lower unit..pushed an 8 ft hydro real nice. Used a lot of gas tho..inherited a 14 ft Penguin day sailor, sold the hydro.

[Cheechako]

The small Hondas have a bad rep too. Have you considered a good used 2 stroke? Much simpler to keep running for the layman. I have a 90's Merc 4 hp I bought for $400 that starts first pull every time. (OK... after winter storage it took 2 pulls!) It was a "closet queen" bought for lake fishing by the PO.....
I once had one of those 2 hp Johnson's... now THAT is a simple OB... no gears! You have to rotate the engine 180degrees for reverse! Used it on a trip to Mexico for 1.5 years with no issues....

[Charlie]

I have 2 2.3 Honda Outboards. I filled one with diesel one year and it didn't run well (for some reason)until I took the tank off emptied it and washed it out with acetone. From there it ran great till my son made a sharp turn and dunked it in the water. We tore it down and rebuilt the carb. He kept calling it a piece of crap engine. Ran fine. Then he dunked it again. We are experts in rebuilding the carbs now. It ran great. Somehow the engine came off the transom and died. My son caught it before it was submerged but it died. Wouldn't start again. This time it was fatal. The connecting rod broke. I have it torn apart and am rebuilding it. I bought another one. When i get the original one fixed I will have twin 2.3 hp engines on a 2.7meter dinghy. Lol.

[unbusted67]

Originally Posted by PDA1

I'm considering buying an engine for our dinghy.

From the reviews I've read (West Marine and others) about the Mercury 3.5 HP it appears the engine is very, very unreliable...if it runs at all.

What's your opinion about the engine?

What other make would you recommend for a dinghy?

Total BS. Any outboard will give you hell if you don't use it and the nature of outboards, boats and dinghies, are to not be used. A diesel can sit for a year but an outboard's fuel tank will get moisture in it, its carb will get gummed up, it's delicate fuel pump diaphragm will dry out.

Look on any forum and you will see people complaining about their unreliable outboards.

I took a merc 5 hp from WM across the great lakes, down the Erie Canal, and Hudson and the only time it didn't start on the first pull is when I submerged it going over a massive wake. Every other time the thing ran like a clock.

I bought the exact same engine for a dingy, the engine and fuel tank had been stored for a year in someone's basement and the thing gave me a headache all year. That's just how these things work. They need to get used.

[Tellie]

Originally Posted by unbusted67

Total BS. Any outboard will give you hell if you don't use it and the nature of outboards, boats and dinghies, are to not be used. A diesel can sit for a year but an outboard's fuel tank will get moisture in it, its carb will get gummed up, it's delicate fuel pump diaphragm will dry out.

Look on any forum and you will see people complaining about their unreliable outboards.

I took a merc 5 hp from WM across the great lakes, down the Erie Canal, and Hudson and the only time it didn't start on the first pull is when I submerged it going over a massive wake. Every other time the thing ran like a clock.

I bought the exact same engine for a dingy, the engine and fuel tank had been stored for a year in someone's basement and the thing gave me a headache all year. That's just how these things work. They need to get used.

True, if an outboard is used everyday rarely is gumming an issue, this is true for most all gas engines. But the nature of cruising for most people doesn't always mean a dingy outboard is used all the time all year round. I see these things sit for extended periods of time all the time.

[MarkSF]

That's why you run it dry, or, even better, drain the float chamber.

[thomm225]

Originally Posted by Tellie

True, if an outboard is used everyday rarely is gumming an issue, this is true for most all gas engines. But the nature of cruising for most people doesn't always mean a dingy outboard is used all the time all year round. I see these things sit for extended periods of time all the time.

Looks like we have a couple winning responses!

My 5hp outboard is my boat engine so it's used all the time at least to get me in and out of the slip.........

Maybe this is why I've never had a problem with it although in the winter I only start is every few weeks but still do not run it dry. I just stop it the normal way.

[MarkSF]

I did a little research on Boats.net. They have the parts diagrams for the Mercurys and the Tohatsus.

One interesting thing is that the replacement carbs for some years do not look the same. Also the same carb is $135 from Tohatsu, and nearly $200 from Mercury.

So I can believe it is possible that some model years from Mercury have a carb that is troublesome, while the Tohatsus don't.

Anecdotally, the sailing club I belonged to had some 5hps in Nissan and Mercury versions. The Nissans would start up on the first pull and run perfectly. Everyone knew to avoid the Mercurys because they were finicky to start, and temperamental when running.

Given that the equivalent Tohatsu is usually $100 or $200 cheaper than the Mercury, and that identical parts seem to be cheaper, why not buy one?

[thomm225]

Originally Posted by MarkSF

Anecdotally, the sailing club I belonged to had some 5hps in Nissan and Mercury versions. The Nissans would start up on the first pull and run perfectly. Everyone knew to avoid the Mercurys because they were finicky to start, and temperamental when running.

That's funny, the 5 hp Nissan and Mercury are the same engine.

[Freedom45]

Originally Posted by Tellie

True, if an outboard is used everyday rarely is gumming an issue, this is true for most all gas engines. But the nature of cruising for most people doesn't always mean a dingy outboard is used all the time all year round. I see these things sit for extended periods of time all the time.

Possibly not just carb gumming issue.
I had a 3.5 merc 4 stroke, bought new. I ran it for about an hour, didn't like my dinghy, bought a new dinghy with new motor. Kept 3.5 , ran in fresh water occasionally and always ran carb dry. Sold "new" dingy, took old ( 1hr run time) motor to island, started up in evening, ran fine, next morning no spark. Electronic ignition coil shot, shop put new coil on couldn't get motor to run right, they gave up, I took it to another shop( a good reputable on) they just shook their heads and said it would cost as much as a new motor to tear it down.
So that's my story.
I bought a Honda 2 hp, runs fine, except the one time I forgot to run carb dry, yep, carb all gummed up, that is a sure thing, so run 'em dry.

Chuck

[thomm225]

Tohatsu and Nissan Marine Outboard Motors


Tohatsu is the manufacturer of all Nissan outboards. They are identical with the exception of branding and brand label (decals). Nissan models are typically slightly higher in price as a result of the premium branding and offer slightly higher resale values. There is no difference in features, specifications, or warranty term.

Tohatsu also has a relationship with Mercury Marine to manufacture portable outboards offered by Mercury Marine below 40hp.

[MarkSF]

Sorry, did you read my post? The parts diagrams clearly show some differences in the carbs.

Also I personally would rather pay $135 than $200 for the same part.

[thomm225]

Originally Posted by MarkSF

Sorry, did you read my post? The parts diagrams clearly show some differences in the carbs.

Also I personally would rather pay $135 than $200 for the same part.

I just took it as more small outboard bashing, but maybe it is a parts difference issue.

I bought a Mercury because I needed the 25" extra long shaft, and there are a couple dealers nearby where I can get repairs done if needed.. Plus it came with a 5 year warranty.

[Cheechako]

One thing about the internet..... the only useful data is that which occurs repeatedly by different posters. There is always someone out there with a "burr under their saddle" and a bone to pick. They had a bad experience. But if repeatedly the post says "my Vega started gulping oil after 35000 miles".... well....where there's smoke there's fire!