[chucker9er]

How do I change the oil in my Briggs and Stratton push mower?

[jdselby1024]

Changing the oil:
Make sure you purchase the right type of oil for your replacement oil. When in doubt, ask where you bought the machine. Or, if you're really desperate, check the owner's manual….
Clean off any dirt around the upper part of the oil tank (where you fill your machine with oil). An old toothbrush comes in handy for this task. Unscrew and remove the dipstick, if your oil tank has one.
Now locate the lower side of your oil tank – a plug found on the underside of your machine. You need to drain out the old oil, and unscrewing this plug will do just that. Prop up your machine accordingly with blocks, providing a tilt that will give you access to the plug. Stick an oil pan or like container under the plug to catch the oil. Ready? Okay, unscrew the plug (you may need a socket wrench) by turning counter-clockwise and let that dirty oil pour out. And I do mean dirty: obviously, you don't want to have your “Sunday best” on when performing a lawn mower tune-up!
Screw the drain plug back on using a clockwise motion. Don't over-tighten, so that you'll be able to get it off easily next time you need a lawn mower tune-up. Rather than over-tightening when you work on your machine, it's better to tighten moderately, then periodically check during the mowing season to ensure that it hasn't loosened through vibrations.
(For machines that have an oil filter) If your machine has an oil filter, replace it as part of the lawn mower tune-up and clean the gasket with which it comes into contact.
Remove the blocks so that your machine is level again.
Fill the oil tank with new oil to the correct level, replacing cap and dipstick.
Refill lawn mower with gas and reconnect spark plug wire.
At this point in the lawn mower tune-up, it's time to start the machine. Let the engine idle and ensure that there are no oil leaks.
Steps for Changing the Spark Plug:
Clean the housing around the old spark plug.
Remove the old spark plug with socket wrench.
Unfortunately, at this point you'll have to check the blasted manual again (don't you just hate that?) What you need to do is ensure that the new spark plug is gapped the way it's supposed to be for your machine. Just measure the gap, then see if the measurement matches manufacturer's specifications for your machine. If it doesn't match (or if there's no gap at all), you'll have to create/alter the gap.
Screw on the new spark plug (not too tight!).

Before changing/cleaning the air filter, first determine whether your machine has a paper or foam air filter. Paper air filters are replaced; while the foam ones are cleaned.

Changing a Paper Air Filter :
Unscrew the cover and remove the paper air filter.
Insert a new paper air filter with the pleat facing out.
Screw the cover back on.


Cleaning a Foam Air Filter :
Unscrew the cover.
Remove air filter unit and discard the old foam.
Clean the air filter unit with kerosene.
Soak the new piece of foam in clean engine oil. Squeeze out the excess oil using a clean rag.
Insert new foam in air filter. Ensure the lip protrudes over edge of the unit.
Screw the cover back on.

[twinkiedooter]

Carefully lean mower on it's side (if it does not have a drain plug) and drain into a big catch basin. Be sure the gasoline cap is on or drain out the gasoline before you do this or you'll have quite a mess. Be sure to also check your air filter and if it's old or dirty get a new one. Same for the spark plug while you're at the lawnmower store. The air filter has a lot to do with compression also and if it's old or worn it may have splits in the rubber gasket and you can loose a lot of compression that way. Just tuned up my mower and treated it to new parts. Runs great now.

[KISS]

Not bad, but I have a couple of additions:

1. Run the engine until it's warm.
2. Put Anti-Seize compound on the oil plug threads.
3. When you fill: It's fill with some oil. Wait 5 minutes. Check level. Repeat until correct.

[KISS]

I also use a large tarp on the lawn. Keeps the spills off the grass.

[MOWERMAN2468]

You can also save the loss of fuel by removing the gas cap and placing a piece of plastic over the filler neck hole, and then tightly screw the gas cap back onto the tank. This keeps the fuel in the tank.
First do as advised above and run the engine for about 5 minutes. Then remove the spark plug before changing the oil. Then there will be a drain plug on the bottom of the engine, remove and drain the oil.