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HomeRepair HelpSimplicity Mower RepairSimplicity Lawn mower won't start Repair
Simplicity Lawn mower won't start
If your Simplicity lawn mower won't start, start with the parts most likely to stop ignition or fuel delivery. A worn or fouled spark plug is the first thing to check, especially if the porcelain is cracked, the electrode is damaged, or there is heavy carbon buildup. Using a spark plug tester will tell you quickly if the plug is producing a strong spark while the engine cranks. If spark is good, the next likely issue is a clogged carburetor caused by old fuel varnish, which is one of the most common reasons a lawn mower is not starting. Try cleaning the carburetor with carburetor cleaner, then consider a carburetor repair kit or full carburetor replacement if cleaning does not help. Old or bad gasoline in the carburetor float bowl can create the same problem. After that, check the start switch for continuity with a multimeter, then inspect the fuel pump, including the pulse line, diaphragm, and check valves. If your Simplicity push mower won't start or your mower has spark but won't start, enter your model number on RepairClinic.com to find the exact replacement part that fits your machine.
01 - Simplicity Lawn Mower Spark Plug
Inspect the spark plug for signs of wear or damage. If the porcelain insulator is cracked, an electrode is burned away or damaged, or there is heavy carbon buildup at the electrode, replace the spark plug. To determine if the spark plug is defective, use a spark plug tester. You should see a strong spark between the tester’s terminals when the engine is cranking. If there is no spark, this indicates that the spark plug is defective and should be replaced.
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02 - Simplicity Lawn Mower Carburetor
The carburetor might be clogged. A clogged carburetor is most commonly caused by leaving fuel in the lawn mower for a long period of time. Over time, some of the ingredients in the fuel may evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the carburetor and prevent the engine from starting. If the carburetor is clogged, try cleaning it with carburetor cleaner. If cleaning the carburetor isn’t effective, rebuild or replace the entire carburetor.
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03 - Simplicity Lawn Mower Carburetor Repair Kit
The carburetor might be clogged. A clogged carburetor is most commonly caused by leaving fuel in the lawn mower for a long period of time. Over time, some of the ingredients in the fuel may evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the carburetor and prevent the engine from starting. If the carburetor is clogged, try cleaning it with carburetor cleaner. If cleaning the carburetor isn’t effective, rebuild or replace the entire carburetor.
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04 - Old or Bad Gasoline
There may be old or bad fuel in the carburetor float bowl. Over time, some of the ingredients in the fuel may evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the carburetor and prevent the engine from starting. If the carburetor is clogged, try cleaning it with carburetor cleaner. If cleaning the carburetor isn’t effective, rebuild or replace the entire carburetor.
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05 - Simplicity Lawn Mower Start Switch
To determine if the start switch is defective, use a multimeter to test it for continuity.
Highly Likely
06 - Simplicity Lawn Mower Fuel Pump
The fuel pump has three ports: the gas in port, the gas out port, and the pulse port. The pulse port is connected to the engine crankcase by a small rubber tube. As the engine runs, air inside the crankcase alternately pressurizes and depressurizes the air in the tube. This pressurized air moves a diaphragm inside the pump and pumps the gas. If the engine oil is overfilled, oil can enter the pulse port line, preventing it from working properly. The fuel pump also has two small check valves on the input and output ports. The check valves prevent fuel from reentering the gas tank. These check valves can fail. To determine if...
Highly Likely
Frequently Asked Questions
Why won't my Simplicity lawn mower start?
My Simplicity lawn mower has spark but won't start. What should I check next?
How do I know if the start switch is bad on my Simplicity mower?
How can I tell if the fuel pump is keeping my Simplicity mower from starting?
How do I find the right spark plug, carburetor, or start switch for my Simplicity lawn mower?
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