Troubleshooting Common Self-propelled Lawn Mower Problems

A red, self-propelled lawn mower with a bag attachment being used to trim the yard.

Self-propelled lawn mowers’ advanced features and ease of use make them a very desirable lawn care tool. However, when your self-propelled mower stops working as designed, it is not always necessary to scrap this helpful tool or seek help from a professional for repairs. By checking a few of the most common problems that could occur, you may be able to diagnose and correct the issue yourself and soon be back cutting your lawn effortlessly.

Trouble on Slopes

One of the simplest fixes when experiencing running issues on a slope is to check the gas tank. The placement of the gas tank allows gas to fluctuate forward or backward when working on a slope. This can cause the mower to slow, sputter, or stop unexpectedly just because the motor is not getting the gas it needs since the fuel has shifted. Simply keep your tank topped off when working on slopes to prevent this issue.

Self-propel Cable

The most common malfunction with these lawn mowers occurs when the self-propel cable breaks or wears out. This cable runs from the handle of the mower to the transmission; the location and high use of this cable make it susceptible to breaking, wearing, or stretching, which can interfere with the mower’s functionality.

Simply locate the hook of this cable, which will be underneath or within the handle, and trace the line all the way down to the end hook that connects it to the transmission. If there is any visible wear or breaks, the cable needs to be replaced. You can find self-propel cables at most hardware stores and changing out the old one requires little more than unhooking it and hooking in the new one.

Not Running or Running Poorly

When the mower itself is having issues, one of the most common causes is simply grass buildup. When mowing the lawn, the motor and transmission can accumulate grass clippings, dirt, and debris. These clog the internal parts and cause the mower to perform poorly or not start at all. The first step in diagnosing this issue is to remove the casing over the transmission and clean any debris or dirt found within.

If the issue is not debris in the motor, you can also check the spark plug. Start by making sure the spark plug is not dirty. Try wiping it clean; if the dirt doesn’t come off, then it needs to be replaced. Make sure the spark plug is tightly secured after cleaning and putting it back in or when installing a new one.

Loss of Speed

If you experience loss of speed while mowing, you should check the drive belt housed within the motor casing. Often, the drive belt can become damaged, loose, or detached, causing speed loss. If any damage is visible on the drive belt, it should be changed. If the drive belt is unattached from the mower, check for damage and then reattach it if none is found.