An engine that won’t start won’t get much grass cut today. Your push mower has a single cylinder engine that is pretty basic. There are not a lot of fancy electronic controls for the electrical or governor systems and it is just a plain gasoline engine.
Every gasoline engine needs these things to run. It requires fuel, compression, air and spark and to troubleshoot why your engine will not start will require a systematic approach to figuring out why it won’t start.
Today, we always start out with the fuel you are using. Is it good and clean fuel? Does it have water in it? Is it older than 90 days? Good clean fuel makes all the difference in the world when it comes to starting your engine. As fuel ages, it becomes less volatile and harder to ignite as the vapors evaporate that ignite easily.
Without a compression gauge, it is hard to tell exactly how much compression your engine has. You can however get an idea of the compression that the engine has by how hard it is to pull the engine over with the pull rope. If there is a good bit of resistance, then you should have good compression.
A dirty air filter will cause your engine to run rich or get too much gas. You need the right mix of fuel to air for the engine to start properly. Check that air filter and if there is any doubt, replace it.
Obtain a spark tester and attach it to the spark plug and spark plug boot. Pull the starter rope and observe the spark. You should see a bright blue or orange color depending on what spark tester you have. If you have good spark, remove the spark plug and check its condition. Also check to see if it is wet with fuel. If it is, replace the spark plug and try to start the engine again.
If you are still struggling to get your lawn mower started, visit our Locations page for a small engine shop near you.