Preventative maintainence - Oil
Black Gold, Texas Tea and Expensive, V 1.0
Don’t neglect your power equipment.
Types of Oil What Does Oil Do Check/Add Oil Change the Oil Types of Oil
Cars TYPICALLY use Detergent oil. Power equipment TYPICALLY uses Non Detergent oil.
The viscosity of oil determines whether it pours like maple syrup or pours like or water or somewhere in between. The lower the viscosity, the thinner the oil. Viscosity changes with temperature. The typical oil viscosity for 4 any 2 cycle engines is 30 W ND, or 30 weight non-detergent. Snow blowers, in particular may require a multi-viscosity oil.
In 2 cycle engines, you typically mix the oil with the gas. In very rare instances, there is an oil reservoir of oil where oil is consumed and automatically mixed. The recommendation here, is to use the oil recommended by the manufacturer. Usually you purchase a small container and add to a gallon of gasoline at least in the US. The TYPICAL ratio is 50:1. See the Fuel FAQ for more information.
In 4-cycle engines there is usually a sump filled with oil. Again, the recommendation is to use a 4-cycle engine oil designed for power equipment and follow the manufacturer’s recommendation.
What Does Oil Do?
Oil lubricates and helps cool the engine. Without oil, you lawn mower would self-destruct; usually by throwing a rod, cracking a head, bending valves and all sorts of expensive things to repair.
Inside the sump, there is a mechanical splasher (oil pump). This splasher, helps cool the oil and gets oil everywhere inside the engine. It helps seal the piston rings, and the rotating seals of the crankshaft and lubricates the lifters and the crankshaft/piston rotating joint.
The more you operate the engine, the more contaminants form from the combustion process. They dilute the oil. Particulates from the internal engine parts, and byproducts of incomplete combustion act like sandpaper on the internal surfaces. Since there usually isn’t an oil filter, we have to replace the oil regularly to avoid engine damage.
Check/Add Oil
I can’t emphasize enough, that you have to check the oil every time. You may loose some or you may gain some. Did I say gain some? Yep, when this happens you probably have gasoline in the oil and that spells trouble.
Since seals are not perfect, your power equipment usually consumes a small amount of oil. If you have blue smoke, the engine is burning oil and it’s not supposed to do that.
How to check the oil
There seem to be two ways to check the oil. Ideally you would want to do it when the engine is cold.
- Dipstick. This seems the most straitforward, but it is also problematic when adding oil. The level should go to the upper mark on the dipstick. Remove the dipstick, wipe off, insert, remove, check and re-insert. You don’t have to do all of this if the mower has been sitting for a long time. Just remove the dip stick, check and re-insert.
- No Dipstick. The oil filler plug usually has two cylindrical protrusions on it or it had a flat knob external appearance. When you remove the plug, you will see a slot, similar to what you might see when checking battery water in your car. The oil level should be at the top of the slot. This plug usually has an O-ring or some type of gasket on it.
Adding oil
Always add a little at a time, wait a few minutes, and check again. Replace the cap or oil fill plug. New oil is sometimes hard to see on the dipstick. The reason to wait is to allow the oil to flow off the sides of the fill tube and dipstick.
Change the oil
How often? About every 30 hours of operation or whatever the manufacturer recommends.
Suggested materials for an oil change
Tarp
Adjustible wrench or open end wrench
Oil
Teflon Tape
Oil pan
Paper towels
Vinyl gloves
A used oil container – for recycling
A kneeling pad
A plastic bag to dispose of waste
This is a good time to consider sharpening the blade, replacing the plug and air filter, and cleaning the deck.
While your collecting the materials, run the lawnmower until it’s warm. Warm oil flows better and removes some of the contaminants off the internal parts of the engine.
The steps below are primarily for a vertical shaft push mower.
I like getting a tarp and placing it on the lawn for this process. It makes for easy cleanup, and you don’t get any oil on the driveway or the lawn.
Turn the engine off and disable starting by removing the spark plug wire. Push the mower onto the tarp and tip the vertical shaft mower over. Clean the area around the plug thoroughly.
The drain plug on a vertical shaft engine is usually a square nutted pipe plug somewhere on the bottom. Loosen the plug. For stubborn plugs, you can use two adjustable wrenches. Used one placed on the plug and another to turn the wrench.
The drain plug for a horizontal shaft engine is usually at the base. There may be two, but you only need to open one of them.
Remove the blade if you intend to sharpen it.
Remove the drain plug and with gloved hands position the mower on top of the drain pan and let it drain. The oil will be hot. Go sharpen the blade while it drains.
After all the oil has drained out, clean the threads of the pipe plug and put some Teflon tape on it. Insert it back into the hole and tighten about 1 turn past finger tight.
This is a real good time to scrape the grass off the deck then take somewhere else and clean and wash the mower bottom and top with a garden hose and some soap and water. Put the blade back on.
You can take it back to the tarp and use the
Adding Oil and
How to Check the Oil procedures above to add fresh oil.
Clean up your mess and dispose of the waste oil per government regulations.
Aside: I typically do the oil change, the blade sharpening, plug change, air filter change and cleaning of the deck in the beginning of the season. The procedure usually occurs at the second cut of the season. It would be best performed at the end of the season.
PM’s welcomed for comments and criticisms.
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