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HomeRepair HelpWalbro Small Engine RepairWalbro Small engine runs poorly Repair
Walbro Small engine runs poorly
When your Walbro small engine runs poorly, runs rough, sputters, or surges, start with the carburetor. A clogged carburetor is the most common cause, especially when stale or ethanol-blended fuel has been left in seasonal equipment. As fuel evaporates, it leaves sticky residue that restricts fuel flow and creates small engine carburetor problems. Clean the carburetor with carburetor cleaner. If that does not correct the engine running rough, rebuild or replace the carburetor with a Small Engine Carburetor Repair Kit. Next, inspect the spark plug for cracks, carbon buildup, or a worn electrode, and use a spark plug tester to confirm a strong spark. A clogged fuel filter is less common but can also cause an engine to lose power or run poorly. If old fuel was left in the engine, drain the fuel tank and replace the fuel filter. Enter your Walbro model number to find the exact replacement part for your specific engine.
01 - Walbro Small Engine Carburetor
The carburetor might be clogged. A clogged carburetor is most commonly caused by leaving fuel in the engine 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 - Walbro Small Engine Carburetor Repair Kit
The carburetor might be clogged. A clogged carburetor is most commonly caused by leaving fuel in the engine 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 - Walbro Small Engine 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 - Walbro Small Engine Fuel Filter
The fuel filter might be clogged. A clogged fuel filter is most commonly caused by leaving fuel in the engine 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 fuel filter and cause the engine to run roughly. If old fuel was left in the engine, drain the old fuel from the fuel tank and replace the fuel filter.
Less Common
Frequently Asked Questions
Why is my Walbro small engine running rough, sputtering, or surging?
How do I fix a Walbro small engine that runs poorly after sitting?
Can a bad spark plug cause a small engine to run poorly?
What should I check if cleaning the carburetor does not stop the engine from running rough?
How do I find the correct Walbro small engine part for my repair?
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