The 7 most common part(s) or condition(s) which contribute to the symptom Small engine runs poorly are listed below. Check or test each item and watch any available videos. If you are still unable to solve the problem you may need to do additional research and troubleshooting. Remember, with our 365 Days. Period.® return policy you can return any part for any reason. So, go ahead and buy it to try it. No other parts retailer offers this unconditional return policy.
For the symptom you selected, these are the most common parts or causes, ordered by the likelihood of fixing the symptom.
If the small engine runs poorly, the carburetor might be clogged or have bad fuel in the float bowl. If old fuel was left in the small engine for a long time some of the volatile ingredients may have evaporated, leaving a thicker, stickier product that is more like varnish or shellac. This sticky fuel can clog up the small jets and ports in the carburetor and it can be difficult to burn making the small engine run poorly. The only solution is to drain the old fuel from the float bowl and thoroughly clean the carburetor with carburetor cleaner. If that isn't effective, replace the entire carburetor.
If the small engine runs poorly it may not be getting fuel consistently. Every engine needs air, fuel and spark. The carburetor has two inputs, fuel from the gas tank and air through the air filter. The carburetor is designed to mix the air and fuel in a consistent ratio so that the engine can run continuously. If the carburetor is not getting enough air or fuel, or if the fuel is blocked inside the carburetor the engine does not start. It can be rebuilt with this carburetor kit.
If the small engine runs poorly,it may not be getting enough fuel. Every engine needs air, fuel and spark. The carburetor rebuild kit can repair the carburetor which has two inputs, fuel from the gas tank and air through the air filter. The carburetor assembly is designed to mix the air and fuel in an exact and consistent ratio so that the lawn mower engine can run continuously. If the carburetor assembly is not getting enough air, or not enough fuel, or if the fuel is blocked inside the carburetor assembly, the engine does not start.
If the small engine runs poorly the spark plug might be defective. All small engines have an ignition coil. The coil is the device that provides spark for the spark plug(s). If the coil is bad power won't get to the spark plug(s). The coil is essentially a small, induction generator. It is mounted next to the flywheel. The flywheel has one or more strong, embedded magnets. As the flywheel spins, the magnet(s) zip past the induction coil, this action of a magnet passing past a coil induces a voltage. Depending on the design of the coil and the strength of the magnets, a stronger or weaker spark can be created and delivered to the spark plug(s). Each time the flywheel spins around a spark is generated. The best way to test a spark plug is to use a spark plug tester. The spark plug should have a strong, visible spark between the electrodes when the engine is cranking. If it doesn't, replace it.
If the small engine runs poorly the flywheel key might have sheared in half or partially. The flywheel key is a small metal shim which fits into a slot in the crankshaft and engages with the flywheel. If the engine stops abruptly due to a problem with the equipment the flywheel key may shear. The only way to know for sure if this is the problem is to remove the flywheel and inspect the flywheel key.
If the small engine runs poorly the air cleaner might be clogged. Remove the air cleaner and replace with the correct filter.
If the small engine runs poorly the fuel filter might be clogged. The fuel filter is usually inline with the fuel line coming from the gas tank. Its purpose is to trap sediment and contaminants from the fuel. Over time it can become clogged and not let enough fuel through. It can't be cleaned but must be replaced if needed.