Can I use E85 in my lawnmower?

Factual Questions
1

Yesterday I spent several hours tearing apart my mower to clean out the bowl, the small screw at the bottom of the bowl where the gas flows in, and the combustion chamber / fuel valve which were caked up with hard black carbon buildup. All of this I blame on bad gas and leaving the mower out in the weather. The last thing I did was to replace the fuel line because the original line was swollen and rubbery inside and no gas was flowing through.

Today I get in a conversation at work about whether cutting the gas tax would work to lower prices. At one point I bring up consumption versus supply and say that cutting back on consumption and demand in the long run is the only way to affect gas prices in the long run.

As a point on consumption I bring up lawnmowers. I go through about 2 gallons per week on a medium sized yard, there are much larger yards out there. When I lived in the sticks I was going through about 5 gallons per week for a 3 acre lot. Multiply this by all the homeowners and contractors and this is a fairly good sized chunk of gas. If we all just suddenly stopped and went to E85 the oil companies would definately feel it.

Any way, this is all very long and complicated and the question is pretty simple. Can I pour E85 into my Briggs and Stratton 5hp lawn mower and expect it to last and perform as well as it does now? Are there any modifications I might need to make first?

2

Don’t do it.

ETA: Forgot to say that they advise using nothing more than E10, which is standard pump gas in many areas.

3

Bummer.

Does anyone know why B&S advises this other than the carb settings and the rubber hose (which is E85 compatible now that I have changed it)?

Anything else I could do to convert?

4

If the parts in the carb are not compatable then no, you shouldn’t use it. If you run E85 then you will lose power to the mower. A 6.5 hp mower would lose about 1 hp.

You should drain your tank after each season to avoid the problems you’re having or put a shutoff valve to the carb. Some mowers come with them. They’re easy to install and will allow you to cut the fuel off and run the gas in the carb until it shuts down.

5

I’ve seen on survivalist boards (you can make your own judgement on credibility) that E-85 will burn hotter than gasoline, which, over time, will cause both metallic and non-metallic parts to fail. One site recommends replacing all steel engine components with nickel-plated or stainless steel.

Also, E-85 tends to be more hydrophilic than E-10, which means you definitely shouldn’t leave your mower outside when it’s humid.

6

Not to mention that E85 is corrosive…

7

I’m sort of surprised that you use that much gas on a 5 horse engine.

2 gallons a week for a medium sized yard? Even 5 gallons for a 3 acre lot seems excesive.

Last time I was mowing, was once a week in Denver. 5 horse Roper or a Toro.

That’s what I would have called a medium sized Suburban yard. I think I might have used a quart a week. Maybe. It would take about 40 minutes. I don’t remember having to refill in the middle of a mow. What do those tanks hold, perhaps16 ounces?

I plow now (yea, no mowing). It takes me about 30-40 minutes to do our drive. It’s a '76 Chevy V8. I’d say it takes about 2 gallons each time. And the truck really gets a work out.

8

But… but if you use E85, you’re contributing to world hunger, polluting the atmosphere, and subscribing to the bourgeois mentality that you have to have a lawn made of non-native species!

:rolleyes:
Seriously though, from what I’ve read, here are the issues with using ethanol fuel in general (they should be about the same for E85):

  1. Your carburetor jets will have to be roughly 40% larger OR you can just use the choke to regulate it, if your mower has one.

  2. Ethanol tends to dissolve many fuel system parts that aren’t made of the right materials. This includes aluminum, many types of rubber, etc… I’m willing to bet that a lot of small engine problems eventually can be tracked back to leaving E10 (gasohol) in the mower too long.

  3. Ethanol has a higher octane number than gasoline, meaning that you’ll want to retune it to get the best performance out of it, since you can’t easily increase compression.

  4. Ethanol has less energy per volume than gasoline, so you’ll use more.

9

as to the chemical mechanism on how ethanol attacks, corrodes, or otherwise degrades aluminum. Can someone 'xplain it to me?

10

It absorbs water.. According to the article it becomes a problem above 10%.

11

Huh, so leaving E10 in the mower over the winter could have been what turned the original hose into silly putty.

Oh well, I guess I’ll have to find another way to stick it to the oil companies without significantly inconveniencing myself (The American Way).

Thanks all for the feedback.

12

One more data point…

Last year I bought a rototiller very cheaply from a person who rebuilds small engines. The rototiller had a 6.5 hp Briggs & Stratton engine. When I went to pick it up, it looked brand new and asked about its history. The rebuilder said that he bought it non-working from the original owner who used it once and could not get it started a second time. The rebuilder took the engine apart, cleaned it and then it ran fine. He said that Briggs & Stratton engines tend to gum up when used with any fuel which contains ethanol. His strong recommendation was that I use a fuel stabilizer which seems to help keep the engine clean. I have been using Sta-Bil and the engine has been running great for over a year.

13

I had old Montgomery Wards Signature 2000 mower from my dad… I use it as a guinea pig to test E85. Now, I have 2nd mower from former owner who sold me the house, I can use E85 on Poulan High wheeled mower as well.

I bought 2 gallons of E85. Poured it into empty tank and tried to fire it up. It won’t start so I decided to adjust jet by opening it by 1 turn. Finally, engine fired up and run but it seem starving. I turned jet outward 1/2 turn. It finally ran normally. I mowed 10,000 SQ FT yard. It use twice more fuel than gasoline. Hey E85 was $1 cheaper than gasoline so I do not see any difference paying for E85 on 2nd trip.

What I am well aware is that plastic float will be eaten away by E85 probably in a long way but not in any parts.

-Exhaust smelled really nice CORN!! made me feel hungry!
-Use twice more fuel (jet was 1-1/2 turns out)
-Kinda hard to start when engine was cold, I had to use choke and several pulls to get it started.
-After several weeks of pure E85, checked sparkplug, it look normal and cleaner.

2 Cycle engine, I haven’t tried that. I know you have to shake gas tank often to keep E85/oil mixed at all time if sits unused. While engine running, vibration and sloshing while working would take care of mixing.

I did not care for what anybody says that it’ll damage engine. My IMHO that small engine manufacture should have prepared for E85 long time ago… Iowa had Gasohol back in 80’s then finally became E85 at some pumps and spreading. I dislike any Small Engine manufacture being stubborn and telling everyone NOT to use E10, E15 up to E85. It’s their problem if we runs out of gasoline or suppose we suddenly have Embargo all over again like 73’ and gasoline shortage. E85 would be plentiful during that time. Sadly, they do not follow Scout Motto… Be Prepared!!!

I am seeing 4 cycle weed whacker and leaf blower engine at hardware store, it’s a really good start to migrate away from 2 cycle engine.

If guy at Family owned Go Cart claims that they ran purely E85 and have no issue… They had million miles on Go Cart engine…

here’s the link:

http://www.ethanoltoday.com/index.php?option=com_content&task=view&id=5&fid=60&Itemid=6

Argentina already running E85 or higher for long time. Here in USA, Get a life!!

Ditch the Myth about E85.

I WOULD use E85 on my John Deere Riding Mower 15hp Kolher engine if necessary.

14

I highly question whether were coming out ahead using any ethanol. I often think about all the diesel that is used to plow, plant, and harvest the crop. Then more diesel to transport it. Then more fuel to refine it etc. I avoid ethanol at all costs, and im in iowa where its .20 cheaper than regular gas. My experience is I get much worse mileage, I dont feel like I come out ahead.
Also worth mentioning south america is more efficient at converting sugar cane to ethanol, than corn into ethanol

15

You could use an electric lawnmower.

16

Even E10 in lawn equipment can cause problems. If you have an ethanol free gas station near you, I would go with that for lawn equipment.

17

As if that is not enough to turn you off, realise that its one thing to get it to run, the next thing is to ensure it does not run lean… It can run lean and give lots of power… See, if it burns hotter, and it burns lean, then …its going to wear out that engine faster…

False economies at every step…

18

They work OK, sort of. I have a rechargeable too, it’s heavy because of the Big Ass battery. They won’t work on anything but a smallish suburban lawn, and will choke on anytime the grass gets a little long. A nice sharp, balanced blade and the high torque RPM that a gasoline engine provides is the way to go here, and plow right through it.

Yeah I had to question the OP on using 5 gallons a week. I don’t use that much in a whole summer. Maybe 2 or 2.5 gal.

19

Never use E85 in an electric mower … a safety tip here.

20

Nor try to plug in a gasoline mower…