There’s nothing quite as frustrating as a beautiful Saturday morning, a lawn in desperate need of a trim, and a mower that simply won’t start. You pull the cord once, twice, a dozen times, and are met with nothing but the sound of your own growing irritation. If this scenario sounds familiar with your trusty Craftsman, you’re not alone. The good news is that most of the time, the issue is something simple you can fix yourself without a costly trip to the repair shop.
Before you resign yourself to a weekend of tall grass, take a deep breath. Diagnosing the problem behind your Craftsman Gas Lawn Mower Not Starting: What to Check is often a straightforward process of elimination. By methodically checking a few key systems, you can often pinpoint the culprit and get back to a perfectly manicured yard in no time. Let’s walk through the most common causes, starting with the simplest and most frequent fixes.
The Usual Suspects: Simple Checks for a Craftsman Gas Lawn Mower Not Starting
It’s easy to overlook the basics when you’re frustrated, but more often than not, the solution is hiding in plain sight. Always start your troubleshooting journey here, as these checks require no tools and just a minute of your time.
First, is there fuel in the tank? It sounds silly, but it happens to the best of us. Ensure you have fresh, clean gasoline; gas that has been sitting in the tank for more than a month can begin to break down and cause starting issues. Next, check the engine shut-off switch or lever. Most Craftsman mowers have a safety feature that kills the engine if the control lever is not held in the “start” or “run” position. Make sure you’re fully engaging this lever when you pull the cord. Finally, take a quick look at the spark plug wire. It should be firmly attached to the top of the spark plug. A loose connection here is a common reason for a no-start condition.
Is Your Mower Getting Fuel?
If the simple checks don’t solve the problem, the next logical step is to investigate the fuel system. Your engine needs a precise mix of air and fuel to run, and any blockage or restriction can prevent it from starting.
Begin with the fuel valve, if your model has one. It should be in the “On” position. Then, move on to the carburetor. The most common culprit in the fuel system is a clogged carburetor, often caused by that old, stale gas we mentioned. Modern gasoline can start to form a varnish-like substance that gums up the tiny jets and passages inside the carburetor. You can try adding a fuel stabilizer to fresh gas and running it through, but a thorough cleaning might be necessary. Another quick check is the air filter. A severely dirty air filter can restrict airflow so much that the engine won’t start. Remove the filter and try starting the mower without it (just for a moment). If it starts, you know you need to clean or replace the air filter.
The Importance of Spark and Compression
For combustion to happen, you need more than just fuel; you need a spark to ignite it and proper compression to contain the explosion. Let’s look at how to check these two critical elements.
The spark plug is a great place to start. Carefully remove the spark plug wire and use a spark plug socket to take out the plug itself. Is the plug fouled with black, oily carbon? Is the electrode worn down or damaged? If so, replacing it with a new one is an inexpensive and easy fix. Even if it looks okay, you can perform a simple spark test. With the wire attached, carefully hold the metal body of the plug against a metal part of the engine block (away from the spark plug hole) and pull the starter cord. You should see a bright blue spark jump across the gap. If you see no spark or a weak orange spark, you likely have an ignition system problem, which could be a faulty plug, a bad ignition coil, or a disconnected kill switch wire.
Compression is a bit harder to test without a special gauge, but you can often get a feel for it. When you pull the starter cord, does it feel unusually easy or lack the typical resistance? If so, you may have a compression issue caused by a stuck valve or worn piston rings, which typically requires professional repair.
Don’t Forget the Safety Switches
Modern lawn mowers are equipped with several safety switches designed to prevent the engine from starting under unsafe conditions. If one of these fails or is out of adjustment, it can mimic a more serious engine problem.
The two most common are the blade engagement switch and the operator presence control. The mower will not start if the blade is engaged. Make sure the control lever or button is in the disengaged position. The operator presence control, often part of the handle, ensures the engine stops if you let go. If this switch is not being depressed properly when you hold the handle, it will prevent starting. Check that the handle is fully in the operating position and that the mechanism connecting to the switch isn’t bent or broken.
Getting Your Craftsman Mower Running Again
In most cases, the issue preventing your Craftsman mower from starting is a simple one. By systematically checking the fuel system for fresh gas and clogs, ensuring the spark plug is in good condition, and verifying that all safety switches are functioning, you can usually identify and solve the problem yourself. Regular maintenance, like using a fuel stabilizer, changing the spark plug annually, and keeping the air filter clean, can prevent many of these issues from happening in the first place. With a little patience and these troubleshooting steps, you’ll be back to a clean-cut lawn in no time.