Putting gas in lawnmower


After finishing mowing the grass, I always let the mower (self-propelled gas-powered walking mower) thoroughly cool off while I sweep up. Then I wash the mower off with the garden hose so it gets put away clean.

Question: Should I refill the gas tank after it cools so that I am washing off any gas that might get spilled on the mower or should I wait and refill the gas next time immediately prior to mowing?

Does it make a difference either in wear and tear on the mower or in safety?



I doubt it matters, I normally fill mine before I use it (that might be a little safer than filling it while it’s hot). Of course, mine has never been cleaned.


Huh? Don’t you use a funnel like everyone else? No spillage.


Yes I use a funnel. However, with my arthritis, I’m not always quite as steady as is best and tend to have a few stray drops get on the mower. Obviously, I never gas up the mower when it is hot!


I really wouldn’t worry, it sounds like you are being more cautious than most people (especially me). It’s good to use a fuel funnel (even though I don’t actually own one) and not fill it while hot (even though I’ve been know to do that too). A few stray drops of fuel are not going to be a problem (I frequently leave a small puddle in the driveway). If I haven’t blown myself up yet, you are probably safe. (-;


Thank you.

Actually, I could/should have worded my question better. My main query is whether storing the mower with a full tank of gas for upwards of a week before the next use is a good, bad, or doesn’t matter idea in terms of how it affects the mower, if at all, and the safety of storing a full mower tank of gas as opposed to the same volume of gas happily sitting in the gas can.

Either way I’m storing one to two gallons total which is far less than is in the car’s gas tank sitting in the same garage. Likely I’m overthinking things and shouldn’t worry beyond using common sense regarding not getting gas on a hot mower!


No grass, no mower just rocks, no yard work Arizona. The “natural look”


I really don’t think it matters if the gas is sitting in the mower or in the gas can. If the mower tank is full or nearly empty shouldn’t matter over a week or two; and the two storage locations are probably equally safe.


LOL That works! My dad long threatened to simply pave it all over and paint it green. grin

Actually, have to admit I’m mowing as many weeds as grass these days. Oh well, it’s all green ground cover and I keep it respectably trimmed and free of harboring mosquitoes, so not going to worry about it until time in the autumn for putting down “weed/feed/seed” combination and let it quietly do it’s thing over the winter. If animated cartoons are to be believed then a perfect lawn should magically leap forth into view one warm day next spring! Don’t think I’ll bet money on it though.


The only exterior cleaning a lawnmower needs is scraping the accumulated grass from under the deck. That should be done after you run it dry, since it has to be tipped on its side. Do this about 3-4 times a year, depending where you live.

When I used a gas mower (elecric now), I only completely cleaned it up before winter. The lawnmower is happy whether is looks grimy or not, and the gas does not care where it is stored. I would avoid getting water in the gas by not hosing down the mower.


Because of the depleting water resources in the SW, Xeriscaping, landscaping with very low water, is now getting very popular. Your county or city should have free inforamtion available on hardy low water plants and shrubs and reducing your lawn to minimum size. We have cut our grass area in half over the years and have much lower water bills as a result. You don’t have to gp to astroturf, although Las Vegas gives you a tax break if you do.


IMO, the less grass; the better. Aside from wasting water, it’s a giant PITA to maintain. I would much rather work on cars than maintain my yard, which probably explains the relative conditions of my cars/yard. I need to cut my grass today, since I avoided doing it all weekend, and went to a local car show instead (not exactly pebble beach, but some interesting local cars):



I’m not sure about small fuel tanks, but in a large tank like cars and airplanes the air space left in a partially filled tank will allow condensation thereby getting water in your gas and would be the only tech reason to store it full. Otherwise do what you like. It’s pretty handy to go out to do the yard work and not immediately need to mess with it.


“Does it make a difference either in wear and tear on the mower or in safety?”

I don’t think so. But you might get a bit more evaporation in the mower gas tank than the storage can. It would be a teeny bit I think, but I always wait until I need it. I own a 2-stroke, so I like to swirl to mix anyway.


If I ever get so anal as to wash my lawnmower after I use it, someone please commit me.

I fill up when I get ready to mow mainly because I’ll probably have to go buy fuel to do it and I was too lazy the day I mowed the grass.



I don’t think that washing down the mower every time you use it is a good idea. It depends a little on the climate. In a damp envrionment, you would get persistent water in some of the crannies and get corrosion. I would tend to just sweep off the mower too unless you got it really sloppy somehow.


Kudos for your attention to detail. And cleanliness.

Leaving the tank 1/2 full or full won’t matter one iota. However, I mix carb or injector cleaner to my yard engine gas can at a ratio of about 1 oz per gallon. It does wonders for keeping the engine running well. I’ve even gotten an old, stumbling snowblower running cleanly with this trick. I then proceeded to use it for another 15 years. It was still running good when I got divorced and had to part with it.

One other thing I do is, at the end of each season, siphon out the gas and run the line dry. I then use the gas in my snowblower, which I do the same with at the end of the snowbloing season.


For what its worth,I Fill mine running.and always have.

its a mower not a classic.

and you should never clean a rider with water,best bet is to blow it off with compressed air. or blower.


If I ever get so anal as to wash my lawnmower after I use it, someone please commit me.

LOL Yeah, except I have a lot of allergies and asthma so if I put the mower away in a closed space like the garage (or the walk out unfinished basement where Dad used to keep it!) without giving it a basic rinse off, then I end up sneezing and coughing non-stop.

The mower is always left out in the breeze (trust me, in this part of the country there is almost always at least some breeze this time of year!) to evaporate nicely dry after its rinse off before being put away. Never had a mower rust yet although Dad did manage to rust the gas tank on the gas powered edger.

Besides, leaving accumulated dust, grass and grunge on a mower like the neighbors do always seems to have them needing new mowers every few years rather than once every decade or more like we do.


Ooooh, I’ll have to try the carb/injector cleaner in the gas at the rate you suggest. That sounds very sensible.

Thanks for the reminder about running the line dry at the end of the season.

BTW, I ended up having to take the mower in for service despite my efforts with changing the spark plug, carb cleaner, fresh gas, etc. Turns out the problem was a broken blade assembly, a solid metal hub (for lack of a better description) the blade fits into. An entire section of the assembly had sheared away. After that part was replaced the machine runs like a dream.

Thanks again for everyone’s patience and help. I’m gradually learning a few basics about how to better care for my car and anything else running on an engine with all I read here and get answered here when I ask questions.