E85 in a 2 stroke.
- Thread starter beerdart
- Start date
- Location
- colorado
interested in the reason behind wanting to run it. unless you are running a turbo or need the cooler burn to avoid high temps, the lowed efficiency and power of e85 outweighs any cost savings.
Quinc
Buy a Superjet
- Location
- California
Trying e85 vs 91 octane in my truck the e85 needs to be a $1+ discounted to make up for the terrible fuel mileage.
- Location
- Western NY
I always heard ballpark 35% richer but no direct experience jetting for it
Joemelia09
Rowdy Joe
- Location
- Nashville, TN
I ran E85 probably five years ago before I knew where to find 110 and I am not sure if the two stroke oil I used or the moisture caused it but the fuel separated from what I am assuming was the ethanol in the tank in a very short time. I pulled the tank and used a few cans of brake clean to clean the nasty slug mess in the bottom of the tank. I am lucky I didn’t destroy a motor trying to save a few bucks. I am sure you can probably figure out how to do it but not worth it imo.
Last edited:
- Location
- Western NY
I ran special e85 stabilizer from Lucas when I used e85 for a turbo yz450 project, it was in a normal vented tank and It worked fine. One thing people told me and I never found out if it was true because we just had a 55gal drum of it, was that you kind of have to buy it that way as a race fuel if you want any consistency. Allegedly you can get anything from e50 to e90 at a regular pump
I've heard that too and it would be one of my main concerns. A guy could just check the ethanol percentage each time and see if it varies, either rejet each time (which would be quite a hassle) or jet for the lowest ethanol percentage you find and mix gas with the ethanol every time to get the same percentage ethanol (also a hassle).
I always suspected the percentage is higher in the summer and lower in the winter, so it might be a non issue for a watercraft that is only run in the summer, but really I have no idea I'd love to hear from somebody that actually knows.
Also get the impression that ethanol is less picky about jetting (as long as it's not lean) but again don't really know. Maybe the difference in ethanol percentage is not enough to actually matter.
- Location
- California
I guess the bigger question is why would you want to run E85 in a 2-stroke. The only place it has been proven to make a difference is in boosted applications.
Can you elaborate on the results you've seen or heard of on a two stroke that is non boosted?
Yeah the consistency issue we come across at work… car barely runs or is setting strange misfire codes…. Then we find the eithonal % is way off and fuel sample looks like white lightning
There would be a better argument for using methanol in top level freestyle boats. Methanol is the only alternative fuel worth messing with. I cant see jet skiers being able to keep up with the extra maintenance of tuning and corrosion control. It takes some talent and discipline to keep anything alcohol powered alive and well.
bored&stroked
Urban redneck
- Location
- AZ
He didn't insinuate anything about it being used in a 2 stroke, he merely said he has only seen it prove useful in boosted applications. From that I get from that statement, is that he hasn't seen any benefit in non boosted 4 stroke applications hence his asking why anyone thinks it would be good for a 2 stroke....
The greatest benefit of alcohol in a large twostroke is its ability to keep the piston temps below their meltdown point while making more power when compared to gasoline. E85 is widely available but not as good as methanol. Mikuni diaphragms have lasted me over 10 years on the E10 in my area. I dont know how E85 or methanol would affect them.
- Location
- Ontario, Canada
I would also suggest keeping in mind that with ethanol of any concentration you run the risk of phase separation. The ethanol will bond to any condensation or water accumulation brought into the tank and as it bonds to the water molecules it turns into a stagnant cloudy, heavy layer that sits at the bottom of the tank. It has barely enough octane capability to let a 4-stroke engine idle but definitely not enough to give it any power (personal experience). Then you need to think about how much of your tank full be it in the ski or in the supply you're using for the ski, has lost octane rating from the separated phase layer. In pump fuels that have 10% at 87 octane, when the ethanol soaks up the water and settles, the ethanol being part of that octane rating you now lose a few points depending on how much has settled. You could drop down to as low as 83. In an environment that is centered around water I would avoid the ethanol as much as possible. Also keep in mind that ethanol will break down the oil film strength, one of it's other uses is a paint thinner. It's not quite as crucial of a concern in 4-strokes because of the oil rings on the piston holding so much volume and being in a constant splash bath, but 2-strokes only have so much suspended in the fuel. Ethanol was one major screw up when it was forced onto the market and it hasn't improved anything. I replaced a carburetor on an ATV a few years back that had 87 pump gas sitting in it for a year or so, the internals were for lack of a better word...rotten. Totally corroded away aluminum emulsification tube, float bowl, the whole deal was just rotten. Just some additional food for thought.
- Location
- Akron, Ohio
I agree with this 100% Ethanol in any 2-Stroke application is normally not good as it reduces the lubrication effect in the oil that is lubricating your crank but it is an especially bad idea in a marine environment. There's a reason most of the guys on here pay extra to run "rec gas" which is ethanol free over pump gas which only has 10% ethanol in most places.