I have a Toro self propelled lawn mower that I am getting ready to put away for the season. The manual says to run it until empty then put some oil in the spark plug chamber. I read an article that states you should not drain the but instead fill up with fresh fuel that has stabilizer added. Thoughts or recommendations?


  • Article seems like good enough advice, but not sure what's with the random scare tactic: "If draining the tank becomes a yearly habit... [you] may accidentally put your family in danger." That's quite a temper the author has if hard starting of the mower in spring is a danger to his family.
    – JPhi1618
    Dec 1, 2015 at 15:09
  • 2
    What makes you think following the manufacturer's instructions is a bad idea?
    – Ecnerwal
    Dec 1, 2015 at 15:22
  • 1
    I haven't had much luck with the fuel stabilizers, just extra $ for "snake oil" IMO. Drain the tank then run it until it quits. Dec 2, 2015 at 6:16

3 Answers 3


The "article" you linked to is written by the manufacturer of STA-BIL, a brand of fuel stabilizer. So I would take the entire thing with an enormous grain of salt.

I don't see how you can go wrong following the advice of the lawn mower manufactorer. Personally for my small engines I switch to stabilized fuel sometime in the fall so that it works its way through all the hoses and into the engine, then when I'm done for the year I run it dry. That way virtually all the fuel is gone and whatever is left should have stabilizer in it.


With the methanol in the fuel I would drain and empty the bowl , over time even with stabilizer some of the fuel evaporates and draws moisture then you need a rebuild or that has been what happened to me. I have found fogging oil to be the easiest way to winterize pull the air filter and fog it until it dies then drain the fuel, In spring fill with fresh fuel and a little shot of starting fluid, mowing in minutes... I did review the add they said nothing about methanol that eats the fuel lines or collecting water, just buy their product in fact start using it a month prior , even though the manufacture might say to drain the tank , great sales pitch.

  • I'd be worried that draining the bowl would sill leave fuel in the small passages of the carb which would then still have the varnish/gum problem. I guess that hasn't been your experience?
    – JPhi1618
    Dec 1, 2015 at 15:05
  • this is why I also do what Henry Jackson does - use stabilized fuel and run it dry. Actually this year I added an extra bit of extra stabilizer to the very last bit of gas - let's see how that works out come spring!
    – aaron
    Dec 1, 2015 at 19:09

One advantage of having the tank full of fuel is that empty fuel tanks and lines may be more likely to collect condensation and rust than lines and tank filled with gas. I imagine that could be an advantage with a car, especially a high mileage car. But with a lawn mower, aren't most of them plastic tanks and rubber lines?

  • the methonal in the gas (here in the pacific northwest) eats the lines and plugs the screen in the carburator I drain all my small tools as I have had to do quite a few rebuilds since they started adding methonal.
    – Ed Beal
    Dec 1, 2015 at 20:15
  • I hear you, we have that same problem here. The Stabil and other ethanol treatment products are supposed to prevent those things from happening. Knock on wood, I have had good luck with those products so far. Dec 1, 2015 at 21:32

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