Few of us have been spared the agony of an unexpected lawn mower engine failure. You pull out the mower expecting to finally get the lawn cut, everything starts right up and is running fine, and suddenly the engine stops working. Don't let this nuisance situation completely ruin your weekend plans. Here is a 7-point checklist of the most likely things you can check and fix yourself. With a little perseverance, you'll have your mower — and your weekend — right back on track.
- Check the fuel status. It might seem like a no-brainer, but maybe you'll be pleasantly surprised to find such a simple fix.
- Add fresh gas. If the fuel level is alright, consider the fuel's age. Many people don't add gas stabilizer to their lawn mower during the busy season, but untreated gas can go stale or sour and lose quality combustion volatiles within a few weeks. Contaminated, thick or sour gas is not ideal, so fill the tank with fresh gas, and you may be back on schedule.
- Inspect the fuel cap. Air is vented into the gas tank through a tiny hole in the gas cap, which, if blocked, can result in a vapor lock causing the engine to shut down.
- Check the oil level. Too much oil in the oil reservoir will foul the plug and prevent smooth engine performance. Drain to the correct level and properly dispose of any excess oil.
- Replace the spark plug. A stuttering engine, strong fuel odors and engine failure could indic
- ate a faulty or worn spark plug. Remove the plug and examine the tip for oil or corrosion. Sometimes a simple plug cleaning suffices, but if you notice the electrode is discolored, dirty or worn, replacing it is the best option. Changing the air filter and oil at the same time you change the plug is good practice.
- Clean the carburetor. A clogged carburetor is often caused by dirty or stale fuel. The carburetor is usually located behind or adjacent to the air filter, and the easiest fix is to clean it with an inexpensive can of carburetor/choke/throttle body cleaner. A small scrubbing brush may be useful. Blow out any residual gunk and liquid with compressed air.
- Remove the carburetor. If the engine is still reluctant to run, removing the carburetor itself is necessary to perform a more thorough inspection and clean. This work is a little more complicated as fuel lines and linkage cables first need to be disengaged.
If none of these issues help to get your mower working again, it might be best to call in the professionals. They'll go further into the inner workings of the mower; for example, checking gas lines, in-line fuel filters and the choke assembly, and will no doubt be able to track down and rectify the problem for you.