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HomeRepair HelpLawn Boy Mower RepairLawn Boy Lawn mower runs rough Repair
Lawn Boy Lawn mower runs rough
If your Lawn Boy lawn mower runs rough, sputters, or the engine runs unevenly after starting, the carburetor is the first place to check. Old fuel can leave behind a sticky residue that clogs the carburetor and causes a Lawn Boy mower engine surging problem or rough running. Start by cleaning the carburetor with carburetor cleaner. If that does not help, the better fix may be a carburetor repair kit or a complete carburetor replacement. Next, inspect the spark plug for wear, carbon buildup, or damage, and test it with a spark plug tester to confirm it is producing a strong spark while the engine is cranking. A weak or failed plug can make a lawn mower run rough even if fuel delivery is okay. If the mower still runs poorly, check the fuel filter since old fuel can clog it and restrict flow enough to cause sputtering. Draining stale gas and replacing the filter often restores normal performance. Enter your Lawn Boy model number on RepairClinic.com to find the exact carburetor, spark plug, fuel filter, or other small engine parts that fit your mower.
01 - Lawn Boy 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 - Lawn Boy 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 - Lawn Boy 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 - Lawn Boy 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 Lawn Boy lawn mower run rough after starting?
Can old gas make a Lawn Boy mower sputter or run unevenly?
How do I know if the spark plug is causing my Lawn Boy mower to run rough?
Should I clean, rebuild, or replace the carburetor on my Lawn Boy lawn mower?
How do I find the right carburetor, spark plug, or fuel filter for my Lawn Boy mower?
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