How to winterize your small engine

What does that mean anyway?  Most of us know that we should winterize our outdoor power equipment (lawn mowers, edgers, tillers, snow blowers, etc…) but why should we do it and how is it done?

Why should we do it (winterize)?

Actually, this has an extremely simple answer…bad gas!  Gas that sits in the tank and in the carburetor goes bad after a relatively short period of time.  In fact, most equipment manufacturers caution the use of gas that is older than 30 days!  It probably comes as a surprise to most of us that gas can start to go bad so quickly but it’s true–especially since the practice of adding ethanol to our fuel supply is mandated in most places.  Ethanol may be better for the environment (that is a whole separate debate), but it is definitely NOT better for our small engines.  Ethanol absorbs water readily.  This moisture in the tank can cause significant damage to a carburetor and eventually the rest of the engine.

In addition to the moisture issues, old gas leaves behind a “varnish like” substance as the gasoline evaporates.  This varnish quickly plugs up the fine passageways inside the carburetor.  The longer the gas sits, the worse this effect becomes…and the more costly the repair bill.


What is the best way to keep bad gas from ruining the carburetor?

This is controversial.  There is an entire industry devoted to the manufacture and distribution of “fuel stabilizers.”  Many of them promise to eliminate the bad effects of ethanol and varnished gas.  Do they work as advertised?

That is very hard to completely determine.  There are very vocal proponents on both sides of that issue.  Many people swear by fuel additives like STABIL, Sea Foam, and Startron.  Others say that none of those products are effective and you’re just throwing your money away if you buy them.  Many of those same people believe that the ONLY WAY to prevent fuel issues is to completely drain the gas tank, gas lines and carburetor if the machine is going to sit for longer than 30 days.


So what is the solution?

Here are our opinions based on several years worth of observations (and observing the results of several hundred customers):

  • Draining the entire system (tank, lines, carburetor) is probably the BEST WAY to protect the engine if the machine is going to sit longer than 30 days.
  • However, YOU probably aren’t going to drain the entire system each time your machine is going to sit more than 30 days!  You may SAY you’re going to run the machine out of gas–you may have great intentions–but you’re going to forget, put it off or run out of time.
  • Even if you do TRY and drain the entire system each time your machine is going to sit more than 30 days, you will probably do it incorrectly.  If you don’t get ALL the gas out, the small amount of fuel left behind is probably even MORE likely to cause problems.
  • For those reasons, we recommend choosing a good quality stabilizer/ethanol fuel treatment and using that EVERY TIME YOU FILL YOUR TANK (especially on any intermittently used equipment like snow blowers and tillers).  We recommend “Startron Enzyme Fuel Treatment,” “STABIL,” or “Sea Foam.”  All of those products are found at most auto parts stores or big box stores.
  • When you use a fuel treatment, make sure you follow the directions carefully…especially the part about running the engine (after adding the stabilizer) for 10 minutes to circulate the fuel.  And, don’t forget to fill the tank 95% full since this will reduce the chance for moisture issues to cause problems.

To summarize OUR recommended solution: If you will really do it, drain the fuel system every time your machine is going to sit for more than 30 days.  However, for most people (like for over 90% of us), when your machine is going to sit for more than 30 days, the most realistic thing to do is to add a quality stabilizer to the gas and follow the instructions on the bottle.


Is that all there is to it?

Yes and no.  Yes, stabilizing the fuel system is the majority of the work.  No, there are other things you should do to your machine:

  • Store it properly:  out of the elements (in a shed, garage or other covered location).  Extra points for climate controlled but probably not necessary.  As a last resort, at least cover the machine with a waterproof tarp (this is better than nothing).
  • Lubricate all pivot points, cables, springs and bearings with the proper grease or oil.
  • We remove the spark plug, spray “fogging oil” directly into the cylinder and then reinstall the plug.  We cycle the piston a couple of times to distribute the oil.  This reduces the chance for rust and corrosion to develop.
  • Clean machine to prepare for the following season



Hopefully you have a better understanding of how and why your machine should be winterized.  Wether you have us do the work or you do it yourself, just remember to do it!  If you follow these recommendations, your machine will run much better when you pull it out of storage for the first time next season.

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