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HomeRepair HelpLawn Boy Mower RepairLawn Boy Lawn mower is hard to start Repair
Lawn Boy Lawn mower is hard to start
If your Lawn Boy lawn mower is hard to start, the problem is usually in the fuel system, not the whole engine. The most common cause is a clogged carburetor from old fuel that has turned sticky and restricted fuel flow, which makes a lawn mower difficult to start or causes a mower hard starting condition. Start by checking the carburetor and cleaning it with carburetor cleaner. If cleaning does not fix it, you may need a carburetor repair kit or a complete carburetor replacement. Next, inspect the primer bulb, since a cracked bulb can let air into the system and make your Lawn Boy lawn mower take many pulls to start. Old or bad gasoline sitting in the carburetor float bowl can cause the same issue, so draining stale fuel is often part of the repair. If the fuel system checks out, test the spark plug with a spark plug tester and replace the plug if it is fouled, damaged, or not producing a strong spark. A failing fuel pump is another likely cause on models equipped with one. Enter your model number on RepairClinic.com to find the exact Lawn Boy replacement parts for 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 hedge trimmer 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 make the engine hard to start. 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 Primer Bulb
Over time, the rubber of the primer bulb can become brittle and cracked. If the primer bulb is cracked, air will get into the fuel system and cause the engine not to run properly. If the primer bulb is cracked, replace it.
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03 - Lawn Boy Lawn Mower Carburetor Repair Kit
The carburetor might be clogged. A clogged carburetor is most commonly caused by leaving fuel in the hedge trimmer 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 make the engine hard to start. 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 make the engine hard to start. 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 - 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.
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06 - Lawn Boy 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 is my Lawn Boy lawn mower hard to start?
My Lawn Boy mower takes many pulls to start. Should I clean the carburetor or replace it?
Can a bad primer bulb make a Lawn Boy mower difficult to start?
My Lawn Boy lawn mower has spark but won't start easily. What should I check next?
How do I find the right Lawn Boy replacement part for a hard-starting mower?
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