A 4-cycle leaf blower is a gasoline-powered machine used to remove leaves, dirt and debris from a driveway or lawn. Unlike an electric version of the leaf blower, it is powered by a gasoline-burning engine that allows the blower to be used in areas not serviced by electricity. A 4-cycle engine operates in the same method as a typical automobile engine. The engine burns straight gasoline, which is in contrast to a 2-cycle engine that burns a mixture of gasoline and oil. A 4-cycle leaf blower engine has a combustion engine that spins a blower fan to move leaves and debris with a concentrated column of forced air.
Gardening and lawn care is typically made much easier with the aid of a 4-cycle leaf blower as compared to using a garden or leaf rake. A powerful jet stream of forced air coming out of the discharge nozzle of the leaf blower simply blows the debris into an area of the operator's choice. The use of a 4-cycle engine makes the operation of the machine much quieter and with less smoke and exhaust pollution than a 2-cycle version of the machine.
A 4-cycle engine operates on a series of four strokes or cycles; these are intake and compression followed by power and exhaust strokes. The entire series of strokes or cycles requires the crankshaft of the engine to make two complete revolutions to complete the cycle of a single piston firing. These engines are typically liquid cooled in large displacement versions, however, smaller engines, such as those used on a 4-cycle leaf blower, are air cooled. Unlike a 2-cycle engine that uses oil mixed with the gasoline to aid in engine cooling and top side lubrication, the 4-cycle uses straight gasoline with the engines oil being added to the engine's crankcase where it lubricates the engine via a pressurized oiling system.
There is much less smoke, noise and oil residue emitted from the exhaust of a 4-cycle leaf blower than from a comparably sized 2-cycle version. The engine also operates at one-half the speed of a 2-cycle engine, making the 4-cycle leaf blower much smoother to operate with less vibration being transmitted to the user's hands from the high-revving alternative. Connected to the crankshaft of the 4-cycle engine is a blower fan commonly called a squirrel cage fan. The fan forces air out of the blower's discharge tube, where it forces the leaves away at hurricane-force wind speeds.