There’s a special kind of frustration that comes with a beautiful Saturday morning, a lawn in need of a trim, and a Craftsman mower that simply won’t start when you turn the key. You’re ready to go, but your machine isn’t cooperating. Instead of the satisfying roar of the engine, you’re met with silence, a series of clicks, or perhaps a slow, labored cranking sound that leads nowhere. Before you resign yourself to a long and potentially expensive trip to the repair shop, it’s worth knowing that many of the issues behind a Craftsman lawn mower key start not working are problems you can diagnose and fix yourself in your own garage.
This common headache is often caused by a simple, easily addressed component in the starting system. From a weak battery to a faulty safety switch, the reasons for a no-start condition are usually logical and systematic. By following a few straightforward troubleshooting steps, you can often identify the culprit and get back to mowing in no time. This guide will walk you through the most common fixes for when your Craftsman lawn mower key start not working, helping you save both time and money.
Before You Begin: The Simple Things to Check First
It may sound obvious, but always start with the basics. These quick checks take only a moment and can save you from unnecessary troubleshooting. First, ensure the mower is on a level surface. Next, confirm that the parking brake is fully engaged. Most Craftsman mowers with a key start have a safety switch that prevents the engine from cranking if the brake isn’t set. Also, check the position of the blade engagement lever (PTO). It must be in the disengaged (off) position for the engine to start. Finally, if your model has a shift lever, make sure it is firmly in neutral.
Diagnosing a Craftsman Lawn Mower Key Start Not Working
When the simple checks don’t solve the problem, it’s time to dig a little deeper. The symptoms your mower exhibits are your biggest clues. Is there complete silence when you turn the key? Is there a rapid clicking noise? Or does the engine turn over very slowly but never fire up? Paying close attention to what you hear will point you in the right direction and make the diagnostic process much smoother.
When You Hear Nothing But Silence
If turning the key results in absolute silence—no clicks, no cranking—the issue is often related to the flow of electricity. Start by inspecting the battery terminals. Look for a white or bluish crusty substance (corrosion) that can prevent a good connection. If you see any, disconnect the battery (negative cable first) and clean the terminals and cable ends with a wire brush and a solution of baking soda and water.
If the connections are clean, the next likely suspect is the battery itself. A battery can lose its charge from sitting idle over the winter or simply from old age. Use a multimeter to check the voltage. A healthy 12-volt battery should read around 12.6 to 12.8 volts when fully charged. If it’s significantly lower, it needs to be recharged. If it won’t hold a charge, it’s time for a replacement.
Another common culprit for complete silence is a faulty safety switch. Craftsman mowers have several, including ones for the seat, brake, and PTO. If any of these switches fail or become misaligned, they break the circuit and prevent the starter from engaging. Consulting your owner’s manual for the location of these switches and how to test them can be very helpful.
When You Hear a Rapid Clicking Sound
A rapid, repetitive clicking noise when you turn the key is a classic sign of a weak battery. The battery has enough power to pull in the starter solenoid (which creates the click) but not enough to actually power the starter motor. Your first step should be to try charging the battery. If a full charge doesn’t resolve the issue, the battery may be at the end of its life and need to be replaced. It’s also a good practice to have your mower’s charging system (the alternator) checked to ensure it’s properly replenishing the battery while the engine runs.
When the Engine Cranks Slowly But Won’t Start
If the starter motor is turning the engine over, but it’s doing so very slowly and lethargically, the problem again often points to the battery. A weak battery cannot provide the necessary amperage (current) to spin the starter at the correct speed. This slow cranking doesn’t allow the engine to build up enough compression to start. Try jump-starting the mower with a known good battery (using jumper cables carefully) or charging your existing battery. If it starts right up with a jump, you’ve confirmed the battery is the issue.
When the Engine Cranks Normally But Still Won’t Start
This situation tells you that your electrical starting system—the battery, solenoid, and starter—is likely working correctly. The problem now lies in either the fuel system or the ignition system. Start with the fuel. Is there fresh gas in the tank? Old gasoline, especially gas containing ethanol that has been sitting for months, can degrade and cause starting problems. If in doubt, siphon out the old fuel and add fresh gasoline.
Next, check that the fuel shut-off valve, if your model has one, is in the “on” position. Also, ensure the choke or primer bulb is being used correctly according to your manual, especially when starting a cold engine. A clogged fuel filter or a faulty spark plug are also very common reasons an engine will crank but not start. Replacing the spark plug and fuel filter are inexpensive, routine maintenance items that can often solve the problem.
Getting Your Mower Ready for the Next Season
A little preventative maintenance can go a long way in avoiding starting troubles. At the end of each mowing season, consider adding a fuel stabilizer to the gas tank and running the engine for a few minutes to circulate it through the system before storing your mower. This helps prevent fuel system gumming. Periodically cleaning the battery terminals and checking the battery’s charge level will also ensure it’s ready to go when you are.
While a non-starting mower can be an inconvenience, it’s often a repairable one. By methodically checking the battery, electrical connections, safety switches, and fuel system, you can usually pinpoint the cause of your Craftsman lawn mower key start not working. With a few simple tools and a bit of patience, you can often get your lawn care partner back in action and enjoy a well-manicured lawn once again.