Blower: Engine Will Idle But Dies At Full Throttle

If the air filter in your leaf blower is partially plugged, it can cause your engine to run, but die at full throttle. The air filter is designed to prevent debris from entering the engine, and over time this debris can accumulate and lead to a clog. When it is clogged, the air filter will allow just enough air through to the engine to idle, but when you engage the throttle, it will shut down. A clogged air filter may cause your blower to idle roughly as well. Air filters can be cleaned to ensure they run properly, and should be inspected as part of your normal blower maintenance routine.

The fuel filter in your leaf blower is located inside the fuel tank and is attached to the fuel line. The function of the fuel filter is to prevent debris in the fuel tank from entering the fuel line and the blower’s engine. If the fuel filter is partially clogged, the engine still may have enough fuel reaching it to start up, and to idle for a while. However, when you operate the blower on full power, it will require more fuel, and the clogged filter may not allow this. Therefore, the engine will die at full power. You will need a screwdriver or hook to pull the fuel line out of the fuel tank to access the fuel filter. Be sure there is little to no fuel in the fuel tank before you begin this repair. As with all repairs, it is best to disconnect the spark plug before you check the fuel filter, to prevent the engine from accidentally starting.

The function of the muffler is to decrease engine noise from your leaf blower. The spark arrestor prevents sparks from the engine from exiting the blower and potentially starting a fire. When your leaf blower expels exhaust gasses, they travel through the exhaust port into the muffler and spark arrestor. Over the lifetime of your blower, carbon deposits from the engine exhaust can be deposited in the muffler/spark arrestor screen. If the exhaust port, muffler, or spark arrested does become plugged with carbon, the exhaust gases can’t exit the engine. This can result in your engine dying at full throttle. These deposits can build up over time, so it is recommended that you clean your muffler/spark arrestor during routine maintenance.

Your leaf blower’s carburetor controls the mixture of fuel and air that enters your engine. If the carburetor is clogged, it may not allow fuel into the engine, which will cause the engine to run, but die when the throttle is engaged. Often you can disassemble your carburetor, clean it, and re-install it to fix this symptom. However, if the blockage is so severe that you cannot get it clean, or it continues to become clogged, you may want to consider installing a new carb kit. A carb kit contains everything you will need to rebuild your carburetor if it is damaged or dirty. To avoid confusion when putting your carburetor back together, it is a good idea to make note of the order in which you remove certain carburetor parts. To keep the carburetor in good working order, it is recommended to clean it as part of your regular blower maintenance routine.

As with the fuel filter, a damaged fuel line can deprive your engine of fuel, causing it to run briefly but die when the throttle is engaged. Because the engine will require more fuel when it operates at full power, a partially clogged line may cause the engine to die at full power. A small crack in the fuel line can also let air in, which can result in this symptom as well.