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HomeRepair HelpCub Cadet Mower RepairCub Cadet Lawn mower runs rough Repair
Cub Cadet Lawn mower runs rough
If your Cub Cadet lawn mower runs rough, sputters, or the engine runs unevenly, the most common cause is a clogged carburetor from old fuel that has turned sticky inside the passages. That buildup can make a Cub Cadet lawn mower run rough after starting, surge at different speeds, or misfire under load. Start by cleaning the carburetor with carburetor cleaner. If that does not solve the problem, rebuild it with a carburetor repair kit or replace the carburetor altogether. Next, check the spark plug for cracks, carbon buildup, or a damaged electrode, and use a spark plug tester to confirm it produces a strong spark while the engine is cranking. A weak or failing plug can also cause lawn mower sputtering and rough operation. If the mower engine surging continues, inspect the fuel filter, since a partially clogged filter can restrict fuel flow and make the engine run poorly. Draining stale fuel from the tank is also a smart step anytime old gas may be involved. Enter your model number on RepairClinic.com to find the exact Cub Cadet replacement parts that fit your mower.
01 - 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 cause the engine to run roughly. 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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02 - 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 cause the engine to run roughly. 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 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.
Highly Likely
04 - Cub Cadet Lawn Mower Fuel Filter
The fuel filter might be clogged. A clogged fuel filter is most commonly caused by leaving old fuel in the lawn mower. Over time, some of the ingredients in the fuel may evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the fuel filter and cause the engine to run roughly. If old fuel was left in the lawn mower, drain the old fuel from the fuel tank and replace the fuel filter.
Less Common
Frequently Asked Questions
Why does my Cub Cadet lawn mower run rough after it starts?
Can a bad spark plug make my Cub Cadet lawn mower sputter or run unevenly?
Should I clean or replace the carburetor on my Cub Cadet mower if it runs rough?
How do I know if the fuel filter is causing my Cub Cadet mower to run rough?
How do I find the right Cub Cadet mower part for a rough-running engine?
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