Ethanol fuel and the little outboards

[1990-270-da-lover]

Hi All, I'm currently looking for a 3.5 to 5hp 4 stroke outboard for our new dinghy. I have looked at all the major outboard manufacturers and have also read alot of reviews on these little buggers. One thing seems to be a recurring complaint among the owners ( these models I've researched; Merc, Yamaha, Tohatsu, Nissan, Honda). The motors run well briefly then quit and are hard or impossible to start. It sounds like the carbs are fouling or varnishing, or something else. I would like to hear from some folks on here that have one of these little outboards, and what model, and how well they run for you, and what if any problems you may have had. Any responses would be much appreciated. Thanks Up Front.

 

[J.Wilt]

I bought a dinghy with a 3.5hp Merc and after reading about all the problems people said they had with the idle issue I sold it before it ever hit the water and bought a older two stroke 5hp Nissan. The Nissan was a great little motor but I still had some issues with that motor idling as well and I didn't like the internal gas tank because the threads would always strip when you screw the cap on to tight. Last year I bought a four stroke 6hp Nissan no problems but it does shake or vibrate more. I have found that it is best to turn the gas flow off and run the motor until all the gas is out of the carbs if you are not going to use the motor for a few days.

 

[fwebster]

I have a Honda 2 hp, a Merc 15 and a Merc 75. All are exactly like every other outboard. If you leave fuel in the carburetor or fuel system, it turns to varnish. Ethanol or non-ethanol doesn't matter except that ethanol fuel eats up fiberglass fuel tanks and goes bad quicker. I don't have any problems with my outboards, but I run the fuel out of them when I flush them by removing the fuel hose from the engine or turning off the fuel supply on the little Honda every time I run them. If you leave fuel in the fuel system for an extended period....longer than a month...... sooner or later you will spend money having the carbs cleaned/replaced. and it doesn't really matter what brand or hp engine because the problem is the fuel, not the motor.

 

[northern]

I have a two stroke 2.5. Ithas never given me ay problems. I have a 5 toe stroke Merc with external fuel tank. It also works well
They look like the same engine you see now both ate 15 years old. 2.5 weightis 29 pounds and the 5 is 44 pounds.

 

[Quint4]

I have a 3.5 Merc that I religiously ran the carb dry at the end of the weekend. It ran perfectly for two seasons.

I got lazy last season and quit my "run dry" routine.

It started running bad and would not idle. I plan to clean the carb this spring and hope to fix the damn thing.

 

[KC_Sundancer]

I am a firm believer in Premium NON_Ethanol fuel in all our small motor toys. Whether they sat all season or not with a drained carb they always fire right up.
To me it's worth the extra few bucks.
I have had a bad experience with Ethanol marina fuel we were not informed of getting. After sitting un-run for 5 weeks, the 15 hp Merc outboard was a slug and would only run for a minute or so then not start. Every time I drained the filter bowl it looked like thin Jello - the ethanol fuel had "phase separated".
Drained all the fuel, new premium and it was back to running perfect, no problems since
I would not be surprised if many of these motor problems you are asking about are not from that very same issue. :huh:
Especially being around the water with built in tanks and temperature swings they would see.

Here is a good article with explanation of "phase separation" and all the factors that help it along: http://www.wellworthproducts.com/articles/phaseseparation.asp

 

[1990-270-da-lover]

Thanks everybody for the helpful insights. I am fairly mechanically inclined and I understand the issues with the rapid decline in fuel quality. I thought it may be the cuprit, and that what I was reading were folks that didn't do their due diligence when it came to draining the fuel out of the system and carb. Makes me feel better knowing it's fuel and not some design flaw when it comes to reducing emissions, or gaining efficiency. I will begin looking for the best bargain I can find from a local dealer, at least that way if I have a problem, I will have some local backup. Thanks again everyone. C'mon Spring!