Leaf blowers are, in essence, small engines attached to a long nozzle. The engine creates a strong burst of air that is used to blow leaves and other debris from the driveway, sidewalk or yard area. The carburetor is a device on the engine that combines fuel and air together to create a combustion. A carburetor that is not properly adjusted may cause the leaf blower to behave erratically. There are many symptoms that point towards a faulty carburetor.
Carburetors maintain engine power even when running at high or low speeds. A leaf blower carburetor that is not adjusted properly will cause the engine to idle roughly. Your leaf blower will jump up and down in your hands or threaten to stop completely. Increasing the fuel entering the carburetor will usually stop rough idling issues.
When you press down on the trigger of the leaf blower the carburetor will feed more fuel into the engine. If you press down on the trigger and there is no acceleration, the carburetor needs to be adjusted. A dirty air filter may create a similar issue, so always clean it before you check the carburetor.
Engine WIll Not Start
A carburetor that has too "lean" a fuel mixture will run rough, but it may keep the engine from starting at all. Before checking the carburetor, remove the fuel line using a pair of pliers to loosen the clamps. A clogged fuel line may cause similar issues.
Adjusting the Carburetor
A leaf blower carburetor will have two or three screws, including a high speed screw marked "H," a low speed screw marked "L" and possibly an idle screw. Turning the "L" screw will adjust the low speed. and the "H" screw adjusts the highest speed. Adjusting the idle screw will keep the engine from running roughly when the engine is running at idle. Some manufacturers recommend taking your leaf blower to a service professional for adjustment.