If your lawn mower won’t start, it’s not always easy to know where to begin your troubleshooting. Fortunately, most mowers are relatively simple machines that can be easily serviced at home, which lets you tackle minor repairs without having to tag in a professional.
There are three main requirements for any gasoline-powered engine to function: fuel, air and spark. If you’re missing one of those key elements, then your lawn mower isn’t going to fire up. Here’s how you can investigate each of those concerns if your lawn mower starts giving you starting trouble.
Check On Sparky
Most lawn mowers have a single spark plug design, which means there’s only one plug to check on. You’ll want to first make sure that it’s snuggly connected to the spark plug wire that feeds it the power needed to fire. If that’s in good shape, you should remove the spark plug and verify that it hasn’t become fouled with carbon or any other dirt or debris.
Fuel It Up
Second on our list of things to check when your lawn mower won’t start is the fuel situation. Your machine’s carburetor mixes air and gasoline together before it’s sent into the cylinder for the spark plug to ignite. Occasionally, the carburetor’s internal components may stick and prevent starting, which you can often fix by gently tapping on the side of the carb.
If that doesn’t help — or if the carburetor looks dry, or doesn’t seem to be getting enough fuel — you’ll want to check your mower’s fuel filter to make sure it isn’t clogged and restricting the flow of gasoline. Finally, ask yourself how old the gasoline you are using is. If it’s been sitting all winter, then it may have separated into a watery mess, which simply won’t work in your engine. It’s time to drain the tank and start with fresh gas if this is the case.
The last tip? Verify that your mower can breathe. The air filter on most mowers has a tough job to do because it’s usually operating in an environment where dust, dirt, and grass clippings are flying around at a high rate of speed. In keeping those out of your motor, the filter sacrifices itself and eventually chokes on all of the particles it has collected, requiring its replacement. To avoid hassles, it’s a good idea to change your filter at the start of each summer season.
If you have trouble starting your lawn mower, using these three troubleshooting tips can get your mower running again and get you back to taking care of your lawn. By following regular maintenance schedules and preparing your lawn mower for summer every spring, you’ll ensure that your mower starts up every time.
Check out all the lawn & garden products available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more lawn mower troubleshooting tips, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photo courtesy of Creative Commons.
Having been bitten by the car bug at a young age, I spent my formative years surrounded by Studebakers at car shows across Quebec and the northeastern United States. Over ten years of racing, restoring, and obsessing over automobiles lead me to balance science writing and automotive journalism full time. I currently contribute as an editor to several online and print automotive publications, and I also write and consult for the pharmaceutical and medical device industry.