The process of checking or changing the oil is a quick and simple one. I've made
this is a fairly lengthy article in order to provide a little extra insight to the process. Although I've done
a lot of typing, the process of changing the oil shouldn't take more than 10 - 15 minutes (or less) if you've prepared
to do the job in advance. Be sure to dispose of the old oil in a safe and responsible manner when you're finished!
I'll begin this article by climbing up on my soapbox...
Folks, aside from keeping the air filter serviced, there is only one thing that would be considered to be more
important in regards to maintenance. Yep! Checking and changing the oil. It is imperative that you keep a sufficient
amount of fresh clean oil in the engine in order to avoid problems and extend engine service life. Insufficient
lubrication due to low oil levels and old dirty oil cause more engine failures than ANY other cause.
The sad fact is that it's totally an unnecessary situation. Money just poured
down the tube! Okay... I'll climb off the box and get down to the subject matter at hand.
CHECKING THE OIL
Proper maintenance should begin with you checking the oil level before you start the machine EVERY TIME. Make it
a habit! With all the different engine models and variations between models, it's important that you know how to
check the oil properly. There isn't much continuity from one manufacturer to another, so I highly recommend that
you read your owner's manual for specific instructions.
Engines with automotive style dipsticks... Most U.S. made engines require that you screw the dipstick all the way
closed, in order to get a correct reading. On the other hand, imported engines require that you simply insert the
dipstick in the filler tube without screwing it in to get the proper reading.
For engines that don't use a dipstick setup, you will usually see a mark or line down in the filler hole to shown
the proper level. Even so, unless you know exactly how much oil the engine is supposed to hold, it's pretty difficult
to always get it right. Also remember that too much oil can cause problems also. If you don't have an owner's manual,
and the exact instructions aren't labeled on the engine, I recommend that you contact the manufacturer for a copy,
or ask them to explain the details for you.
CHANGING THE OIL
"How often should I change the oil?"
Again, the best answer to that question is to follow the manufacturer's instructions. However, as a safe rule of
thumb, change it after every 20-30 hours of usage or sooner if it appears dirty when you check the oil level.
"What kind of oil do I use?"
Hopefully without sounding like a broken record, you should use oil of the specific rating recommended by the manufacturer.
Brand is not too important as long as you stay with a nationally recognized product. There is some debate between
manufacturer's as to what viscosity rating should be used for small engine applications and whether a multi-viscosity
type oil should be used at all. Some will recommend a specific viscosity, while other will recommend that you use
a multi-viscosity type. A good generic approach would be to use a straight 30 WT for warmer seasons and for winter
or cold temperature operation, 10W30 should suffice.
Let me add this... whether the manufacturer recommends a multi-weight or not, any clean fresh oil of good quality
will be better than the old dirty oil EVERY TIME!
TOOLS FOR THE JOB
To change the oil, you will need some or all of the following:
- Drain/Catch Pan
- Socket set and or crescent style adjustable wrench
- Specialty tool to remove the oil drain plug (Some engines)
- Oil Filter Wrench
- Large channel lock type pliers (optional)
- Shop towels, old rags, or paper towels to clean up any spills
*Note - It's a good idea to check to make sure you have the necessary tools BEFORE you start the job!
DRAINING THE OIL
I recommend that you warm up the engine prior to draining the oil. Warm oil will drain much quicker than cold oil,
especially if it's really thick and dirty. If you are lucky, the oil drain plug will be located in a place with
easy access and might even have an easy to use drain valve installed. (Some companies offer this as an option or
accessory, which is great if you plan on doing your own oil changes regularly) However, many times it will be located
on the bottom of the engine, so that means you have to first prepare a way to gain access to it.
IMPORTANT! Remove the spark plug, so there is no chance of having
the engine start with your hands close to the blade(s) or other moving parts.
Most riding mowers will have the drain plug located on the side of the engine and even if it's located underneath,
it usually pretty easy to get to.
Rotary Style Mowers / Equipment with Drain Plug Underneath
Depending on the manufacturer, there could be several different types of oil drain plugs, most of which can be
removed with common tools. Some however will have a special "Allen /Hex Head or Torx Bit " style drain
plug. For those, you will need to own or purchase the correct tool. (It's an especially good idea to find this
out ahead of time.)
Remove the air filter so that it can't be saturated with oil, and tip the machine carb side up ( in most cases)
to access the drain plug. Don't tip it too far or turn it upside down... a bad situation can result from this.
Support the machine in position with jack stands or suitable blocks.
Drain the oil into a suitable container and replace the drain plug. Don't over tighten the plug, but be sure to
get it snug so it won't come out later during use.
Don't Forget The Oil Filter!
Change the oil filter every time you change the oil! In the shop, if the oil filter is exposed where I can get
to it, I usually use a set of large channel lock type pliers to remove the oil filter. Otherwise, I prefer to use
a "strap style" oil filter wrench. However, on some engines it could require the use of a specially sized
oil filter wrench to fit on the bottom of the oil filter
INSTALLING THE OIL FILTER
First, clean the mounting surfaces where the oil filter attaches to the engine. Lightly coat the rubber gasket
with oil and install the oil filter. Screw it on until it just makes contact with the mounting surface and then
turn it an additional 1/4 turn. If it's over tightened, it could cause a leak or be a real problem to get off the
Reinstall the air filter if it was removed and refill the engine with the proper amount of fresh clean oil. Replace
the spark plug(s).
**NOTE - In the shop, I don't replace the spark plug(s) until I'm SURE that the correct amount of oil is back in
the engine! This is just a precautionary measure to insure that the engine will not be capable of starting without
oil in it should I get side tracked with something else during the oil change.
Start and run the engine while watching for leaks. After a minute or so, stop the engine and recheck the oil level.
(This is an important step for engines that have oil filters). Also keep in mind that sometimes if the equipment
is tipped up in order to access the drain plug, you may have gotten oil in the exhaust system, so the engine may
blow white smoke for the first few minutes it runs....
With no oil leaks and the correct oil level, that's it... your done!