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HomeRepair HelpCub Cadet Mower RepairCub Cadet Lawn mower won't start Repair
Cub Cadet Lawn mower won't start
If your Cub Cadet lawn mower won't start, start with the most common causes first: a bad spark plug, a clogged carburetor, stale fuel, a faulty start switch, or a failed fuel pump. Check the spark plug for a cracked insulator, damaged electrode, or heavy carbon buildup, and confirm spark with a spark plug tester while the engine is cranking. If your Cub Cadet lawn mower has spark but won't start, the carburetor is a likely problem. Old gas can leave sticky deposits in the carburetor float bowl and passages, which is a common reason a lawn mower not starting turns into a fuel delivery issue. Try cleaning the carburetor with carburetor cleaner, then rebuild it with a carburetor repair kit or replace the carburetor if needed. If the mower still will not fire, test the start switch for continuity and inspect the fuel pump, including the pulse line, diaphragm, and check valves. Whether your push mower won't start or your riding mower won't start, enter your model number on RepairClinic.com to find the exact Cub Cadet replacement part that fits your machine.
01 - Cub Cadet 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 - Cub Cadet 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 - Cub Cadet 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 - Cub Cadet Lawn Mower Start Switch
To determine if the start switch is defective, use a multimeter to test it for continuity.
Highly Likely
06 - Cub Cadet 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 Cub Cadet lawn mower start?
My Cub Cadet lawn mower has spark but won't start. What should I check next?
Can old gas keep a Cub Cadet mower from starting?
How do I test a Cub Cadet lawn mower start switch?
How do I find the right Cub Cadet replacement part for my mower?
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