There’s nothing quite as frustrating as a beautiful Saturday morning, ready to tackle the overgrown lawn, only to be met with silence from your mower. You pull the cord again and again, but the engine just won’t turn over. Before you resign yourself to a costly repair bill or start shopping for a new machine, take a deep breath. In most cases, the solution is simpler than you think.
When your Craftsman push lawn mower will not start, the issue is almost always related to one of three things: fuel, spark, or air. These are the fundamental elements any small engine needs to run. By systematically checking these areas first, you can often diagnose and fix the problem yourself in just a few minutes, saving both time and money. Let’s walk through the logical first steps to get you back to mowing.
The First Thing to Check: Your Fuel System
Old or contaminated gasoline is the single most common culprit for a mower that refuses to start. Today’s ethanol-blended fuels can break down in as little as 30 days, forming a gummy residue that clogs the carburetor’s tiny passages.
First, check the fuel level. It sounds obvious, but it’s an easy thing to overlook. Next, take a look at the fuel itself. If it’s been sitting in the tank for more than a month, it’s a good suspect. Drain the old fuel from the tank and the carburetor (if your model has a drain bolt), and fill it with fresh, high-octane gasoline. For long-term health, consider using a fuel stabilizer with every fill-up.
Inspecting the Spark Plug
The spark plug is what ignites the fuel-air mixture in the engine cylinder. A faulty or fouled plug can easily prevent starting. Carefully remove the spark plug wire and use a socket wrench to unscrew the plug from the engine head.
Inspect the electrode at the end of the plug. Is it covered in black, oily soot or a white, ashy deposit? Is the gap extremely wide or the electrode damaged? If it looks worn or dirty, it’s a good idea to simply replace it with a new one. They are inexpensive and a fresh plug can make a world of difference. Before installing the new one, ensure it is properly gapped according to your mower’s manual.
When Your Craftsman Push Lawn Mower Will Not Start: The Air Filter
A clogged air filter starves the engine of the oxygen it needs for combustion. Locate the air filter cover on the side of the engine—it’s usually a black plastic box held on by a single screw or snap clips. Remove the cover and take out the filter.
If it’s a paper filter, hold it up to the light. If you can’t see light passing through, it needs to be replaced. If it’s a foam filter, wash it gently in warm, soapy water, rinse thoroughly, and let it dry completely before adding a few drops of clean engine oil and squeezing it to distribute the oil evenly. A clean air filter is a simple and vital piece of maintenance.
A Few More Simple Checks
Before you call it quits, run through these quick visual inspections. Ensure the engine stop lever or bail lever (the handle you hold down to keep the engine running) is fully engaged. If the safety lever isn’t depressed, the engine is designed not to start. Also, check that the spark plug wire is firmly attached to the plug. It can sometimes work its way loose after bumping something. Finally, check the oil level. Many modern mowers have a low-oil safety sensor that will prevent the engine from starting if the oil is too low.
By starting with these simple checks—fresh fuel, a good spark, and a clean air filter—you’ve addressed the vast majority of no-start issues. Regular, simple maintenance at the start and end of each mowing season is the best way to prevent these headaches. With a little patience and these basic steps, you’re well on your way to a smoothly running mower and a perfectly manicured lawn.