Robin Subaru 4 cycle - Gas with ethanol OK?

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gobigkahuna

New Member
Are these engines designed to use gas that has ethanol added? Or do I have to use non-ethanol gas (which is more expensive here)?
 
Hi gobigkahuna. I have 4 strokes and 2 strokes. I use pump gas, probably 10% ethanol. I don't think these engines were engineered for gasoline with alcohol, or maybe it's the sulfur content or other additives. To prevent any problems I add: gumout 2x concentrated, STP carburetor cleaner and stabil to the gasoline for my small engines.
 
I can get "non-ethanol" gas but it costs more and isn't as easy to find. Just wondered if it mattered with these engines as they are pretty simply built I thought they might not be adversely effected.
 
Run the non ethanol fuel if you can get it. Even if you pay more you are going to use so little it wont matter.
 
Yeah, that's kind of what I thought. Between my boat, truck, lawnmower and now my m-bike, everything uses a different type of gas. Just was hoping that two would use the same kind. ;)
 
Hi. I think the gasoline with ethanol does not hurt the small engines. The carburetor jet clogs easily with the residue or something in the gasoline. The gasoline with ethanol is more water soluble than gasoline by itself, so the gasoline with ethanol has more water dissolved in it before the water and gasoline layer out. This may be a concern.
 
In my corner of Arizona all of the gas companies use way more alcohol than is allowed. There is ONE pipe delivering both regular and premium fuel to my location. For every one. Amoco to the smallest mom and pop station.
I use seafoam or I replace the carb gaskets. And sometimes have to buy a new carb when the disolved gaskets can not be removed from the passages. Cough! Walbro Cough!
For example about 6 mos ago the $900.00 fuel pump in my van dissolved in the alcohol laden fuel bought from a 7/11.
Ouch!!!

All the local auto supply stores were sold out of every intank fuel pump.
It took about a month to get a new pump.
 
The earlier Walbro carbs used a rubber based pump/valve diaphragm, the ethanol plays havoc with these. The composite versions, either light brown or purple/blue are ok with ethanol. The newer carbs have these. Your guess is a good as mine whats in the China clone carbs. The stuff from Japan I am sure is ok. Anytime you can avoid ethanol, do so!
 
You're lucky if you can even get gas without the E10, not available here. If it's not a huge bother I would definitely run it in that engine when you can. The EHO series engines tend to build up carbon.

On another note, Spad mentioned Seafoam and I've had great luck with it. I was able to rehab and completely revive a used EHO35 with it without teardown that had been badly abused. I don't use it as a gas additive though but as a periodic engine treatment.
 
Just was hoping I could avoid having 3 separate jerry cans in the garage. ;) We have a lot of fishing boats here so non-ethanol gas is available (although it's 20 cents more expensive and only a couple stations carry it).
 
There is a small engine repair/lawn equip shop etc near me that has been in business for 35 years, also an authorized R/S dealer. The old boy who runs it told me in his experience what he's seen, E10 was nothing but trouble for small engines, particularly those with diaphragm carbs.

Now they're talking about bumping it to E15.
 
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I use regular gas no ethanol blends in both of my Subaru engines. I also use a little Marvel Mystery Oil added to the gas for upper cylinder lube. Ethanol used in small 4 cycle engines will cause valve problems. You need an additive for upper cylinder lube.
buzzard
 
As you have probably gathered from previous posts, the ethenol issue isn't with the engine but with the soft parts in the fuel system - particularlly the fuel lines and diaphragm carburetor. The newer composite diaphragms are better, but they still get attacked by the ethenol. This also goes for fuel lines too, even Tygon. I read somewhere that some folks store their engines by first draining the fuel and then putting in a mixture of Coleman stove fuel and Stabil followed by a short run to fill up the fuel lines and carb with this mixture. I haven't tried it myself yet, but plan to. I almost always have to rebuild the carbs and replace the fuel lines in the spring on any of my equipment that has a Walbro carb on it.

cannonball2 said:
The earlier Walbro carbs used a rubber based pump/valve diaphragm, the ethanol plays havoc with these. The composite versions, either light brown or purple/blue are ok with ethanol. Anytime you can avoid ethanol, do so!
Click to expand...
 
Coleman is stable for years, makes a good storage fuel if putting up dry is not possible. I actually ran a few gallons though my R/C gassers with good results. Not good for general use though as it is fairly low octane.
 
Get the little, or no ethanol. Ethanol eats up small engines. Mostly the carbs. I ended up buying a whole new engine for my boat cuz the ethanol eats them.
 
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