When to change mower oil

[Ursatdx]

I'm a fall change guy on all OPE. Filter if it has one.
Strange to hear so many who neglect or fail to change the oil in any ICE.
Guess I'm old school but why not? What"s it hold? A qt?
I'm a T6 guy in anything without a cat.
Once a year, need it or not.
ATV, Power washers, Lawn tractors, Gensets.........
Silly not to.
I also sharpen my blades a ton. Two sets. One's always at the ready.

 

[PW01]

All things considered, I guess I’ll just do it end of season

 

[Kira]

The oil is so black come Autumn. Being close to the ground makes me think a lawn mower is exposed to more dirt.
Black...grit...OUT.

 

[Warlord]

Oh no not the dreaded mythical acid sitting over winter eating up the engine. It’s a wonder my mowers aren’t melted lumps of steel come springtime.

 

[Cujet]

Oh no not the dreaded mythical acid sitting over winter eating up the engine. It’s a wonder my mowers aren’t melted lumps of steel come springtime.

Exactly. Any quality oil has a high enough TBN to combat acids for many years of use.

 

[Lubener]

When in doubt, do. It's only 20-24 ounces of oil.

 

[jeepman3071]

Oh no not the dreaded mythical acid sitting over winter eating up the engine. It’s a wonder my mowers aren’t melted lumps of steel come springtime.

I have to chuckle a little when I see comments about oil sitting in a mower over winter causing issues. Most of the mowers and equipment I see are 10+ years old and my customers have never changed the oil in them or even added any. Now, I certainly agree that seasonal maintenance is the key to longevity, but oil sitting in an engine over winter causing damage is a whole different level of paranoia.

As for the OP: most manufacturers say to change the oil every 50 hours, in my experience that seems to be once every two years for the average homeowner with an average sized yard and a push mower. It really comes down to personal preference and usage. Some people put on many more hours in a year and operate in harsh conditions, others do not. I have customers who are regimented about maintenance and bring their machines to me every season, and I have others who own 15+ year old mowers that want me to fix the broken wheel but not spend a dime on an oil change.

 

[jeepman3071]

The oil is so black come Autumn. Being close to the ground makes me think a lawn mower is exposed to more dirt.
Black...grit...OUT.

It's not so much being close to the ground as it is the dust kicked up by the blades. One season my yard was extremely dry, I checked the air filter after 5 mowings and it was packed solid. Normally at the end of the season I can knock the dirt out of the filter, blow it out with the compressor and it looks like new again.

 

[Ride_Red]

I'm in the "change it in the fall" crowd. In the spring, start it up and mow all summer.

I used to change it every year, but the oil still looked nice and clean after about 30hs of total use. Now it's every couple of years.

 

[blkwtr]

I have two John Deere riding mowers. I just follow the Owners Manual recommendations. The L100 with a Briggs and Stratton has 1,630 hrs. and gets changed every 50 hrs.. The X590 has a Kawasaki with 260 hrs. and gets changed every 100 hrs..

 

[BMW Dom]

I do it every 25 hours ( I don't measure the hours, but I do it every other month) , but every 50 hours on the OHV ones should be fine. Personally, I just use the cheapest 10w-30 synthetic I can find.

 

[nomas]

Oh no not the dreaded mythical acid sitting over winter eating up the engine. It’s a wonder my mowers aren’t melted lumps of steel come springtime.

Preach it !

 

[Duffyjr]

The way oil looks on a dip stick is quite different than it looks sitting in a drain pan.

 

[Hermann]

Both of my mowers are coming up on two years. Oil is still clear on one to slightly yellowish brown on the other. I guess it is time. Don't want those acids ruining my 18 year old Chonda. I even have the B & S vacuum pump thingy, so easy peasy

 

[busdriver]

I change the oil in my 42 inch Cub Cadet in the fall..It's going on 12 years old and so far no engine problems...

 

[Braapdaddy]

Every 100 hours on my Cub Cadet with a Kohler Courage 18hp with leftover 15w40 Lucas Magnum from SuperDuties it currently has nearly 450 hours on the ticker

Changed rear axle Hydro fluid at 200 hours with Lucas 20w50 major improvement on sound and longevity when hot on hills vs the factory fill

 

[chemman]

I change the oil in all my mowers (2 self propelled Toros and a Craftsman/Husqvarna rider all with B&S engines) every holiday (Memorial Day, 4th of July, Labor Day and then when I put them away for winter). This was recommended to me by the Toro Dealer I bought my first self propelled Toro from 25 years ago. Other than rebuilding the carburetor on the 25 year old one about 10 years ago, I've never had any engine problems and none of the mowers burn oil.

Granted the self propelled Toro push mowers normally do not see more than 3 or 4 hours a month, they both have been heavily used when the riding mower has been out of commission due to an electrical problem, a bad belt or a bad bearing on the deck. I do have an hour meter on the riding mower and the hours between oil and filter changes is right about 25 hours. All of them get 10W30 Havoline Conventional and as soon as I run out of that, they will all get Havoline Life Long Full Synthetic 5w30. Oh, and I change the spark plugs whenever they need it.

 

[MotorFan]

I change our Honda self propelled push mower oil annually in the fall at the end of the cutting season.

 

[AutoMechanic]

I’ll probably change all of our mowers oil today. We do it once a year. Typically whenever I get to do it. Usually towards the beginning of the season. I like having that very fresh oil throughout the season then I’ll drain it come next year and repeat. Same with the plug.

 

[bunnspecial]

I usually do it in the spring. There's no particular reason why-it's just that if I'm going to have to get the mower lifted up to pull the blade for its spring sharpening, I figure I might as well turn the thing all the way over and dump the oil out while I'm at it.

To be honest, I'd guess 90%+ of push mowers never have their oil changed(and B&S even advertises liftetime oil in their current engines as others have mentioned) so changing it at any point in the year puts you ahead of most of them out there.

I've "regressed" to 2-stroke Lawn Boys so don't have to worry about them at all now. With that said, I was getting ready to sell the Murray-branded B&S "never change" my wife bought new in 2018 and noticed that there were some pinholes of rust in the deck. Before I came along and started using it, I don't know what type of care it got, but I've certainly not abused it. It's also a $200 mower, but still the engine is still going strong while I'll go out on a limb and say that the rest of it is basically EOL.