Changing & Draining Your Walk Behind Lawn Mower’s Oil Main Image

Checking your oil is one of the most important things that you can do to extend the life of your lawn mower engine. In this video, Pete will show you how to properly check the dipstick in a Honda lawn mower, but this process can be used for any rotary-style lawn mower.

Here's a quick recap of the video:

Checking the Oil Level Using Your Dipstick

  • NEVER ever ever (you get the point) run your mower without oil or with low oil. Always check your mower's oil level BEFORE running it, otherwise you could do serious damage to the engine which could result in costly repairs (or you might need a new engine altogether)
  • Carefully unscrew the dipstick (or pull the dipstick out, it depends on the mower). Be careful -- some mowers have a dipstick tube that also screws into the mower. Make sure you're only unscrewing the dipstick and not both the dipstick and the tube!
  • Take a clean rag or paper towel and wipe the oil off of the dipstick. Then, carefully insert the dipstick back into the tube (as far as it will go) and hold it there for a few seconds. Remove the dipstick and make sure that the oil level is at the "full" marking.
  • Clean the dipstick off again with your clean rag and insert the dipstick back into the mower, hand tightening it until it is snug. Do not over tighten or you may damage the dipstick or the tube.

We also briefly touched on the subject of checking your fuel. You should always run fresh fuel in your mower to ensure that you're getting the most out of your engine. If you decide to run old fuel, please note that this could affect things later on, as the high content of ethanol in fuel attracts water which could damage your engine. Also, carburetors, fuel line and tanks tend to collect gunk that can slow fuel flow and cause your mower to stall or not start.

Draining the Oil Out of Your Lawn Mower

  • Now we're ready to drain the oil out of our mower -- but we want to start it up first. After checking the oil to make sure that the engine is safe to run, we'll start up the mower and let it run for a few minutes. This will warm up the oil and allow it to collect any sediment that may have settled into the crankcase. Warming the oil will also allow it to flow more freely when we're draining it.
  • Grab a pan or tub to catch the oil. In our local shop, we're big on re-using things, so most of our pans were retired out of our kitchens years ago. For larger machines, we'll use oil drain pans that you can pick up at your local hardware store that allow you to dispose of the oil properly.
  • Carefully tilt the mower over with the air filter pointed up. If you tilt it the other direction (with the air filter down), the air filter will become saturated with oil and this will make it difficult to start your mower later and will most likely cause your engine to smoke. We recommend that you replace your air filter if this is done by accident.
  • After you've tilted the mower over, place the pan underneath the mower. Unscrew the dipstick and let the oil drip down into the pan.
  • You're never going to get 100% of the oil out of the engine, but it's a good idea to let the oil drain for 5-10 minutes until most of it has drained out. We recommend that you perform other tasks while you're waiting for the oil to drain, like cleaning the underside of the deck, sharpening your lawn mower blades or checking your transmission.

After the draining process is complete, you'll need to screw the dipstick back in and make sure that it is snug (again, not over tightening it). Then, tilt the mower back on all four wheels.

Adding New Oil

For instructions on adding new oil, please read our article on installing new oil into your engine.