Gardening: Ethanol is Killing Your Lawn Mower

Cary, NC – A couple of weeks ago, I wrote a story about getting ready for Spring. One of the tips was “service your lawnmower.” So, I serviced my lawnmower. What I found out will shock you.

Ethanol is Killing Your Lawn Mower

Ethanol, of course, refers to fuel made from plant material such as corn and sugarcane. It’s a renewable fuel source. Cars run on it just fine.

But ethanol is killing your lawn mower.

According to Tim Carver of the Chicago Tribune:

Small engine repair shops love ethanol because it provides them with a steady stream of business. But if you get one of these shop owners to open up with you, he’ll probably tell you he doesn’t use that gasoline in his own small engines.

When I took my mower to Cary Mower & Saw, they not only told me about the dangers of ethanol to small engines, they gave me a handout explaining the issue and what to do to prevent damage my lawn mower. That’s how we roll in Cary.

The Problem With Ethanol

The problem with ethanol is that it absorbs water.

This happens when the fuel is more than 30 days old, like the old fuel in your lawn mower, leaf blower and gas can. Water fouls the carburetor, preventing the engine from starting. The carburetor will need to be drained, cleaned and possibly replaced.

I used to add a fuel stabilizer to my gas can, but it doesn’t work on ethanol.

Three Tips for Lawn Mower Fuel

These tips apply to all your outdoor equipment small engines – lawn mowers, blowers, tillers, chain saws and chippers.

  1. Use Ethanol-Free Gasoline
  2. 93 Octane – Premium
  3. Don’t use gas more than 30 days old

Here are two locations in the area that sell ethanol-free gas from the pump:

  • Shell – Highway 64 and Lake Pine
  • Marathon – NC 54 and Airport Blvd.

You can also purchase ethanol-free canned fuels like MotoMix and TruFuel at garden stores, home improvement stores and lawn mower and small engine repair shops.

93 Octane (Premium) fuel stays fresher for longer than 87 octane (Regular). Since you’re only buying a small amount, give your small engine the best. If you can’t get 93, use 91. Never use gas with more than 10 percent ethanol like E85.

Finally, buy small quantities of gas. Don’t fill up a five-gallon tank to last until autumn. Think more like a half-gallon that you need to refill every week or two.

If you have old gas hanging around from last fall, safely drain your gas equipment and recycle the fuel at North Wake or South Wake Household Hazardous Waste Facilities free of charge.


Story by Hal Goodtree. Photos by Hal Goodtree and by Ansik

The Gardening column on CaryCitizen is sponsored by Garden Supply Company on Old Apex Road in Cary.

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2 replies
  1. Gary
    Gary says:

    Have 3 powerheads for my lawn tools hanging in the barn to remind me. Go back and forth CA to OK twice per year and take a 5gal can as a precaution against problems. Never needed the gas for an emergency but I always have nonethanol supply at each end. Newest powerhead has lasted over 5 years with no problems. Phillips 66 in the Midwest.

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