Engine - Most weed wackers use a 2 cycle engine to power the weed wacker. Parts that are commonly replaced on Two cycle engines include; spark plugs, fuel filters, primer bulbs, and pull cords.

Motor - In the case of electrically operated weed wackers, a motor is used to create the rotational motion of the trimmer head.

Control - The weed wacker control typically includes and on/off switch and a throttle control to control the speed and power of the engine. Some controls allow for the throttle to be locked open while starting.

Shaft - The weed wacker shaft supports the engine, trimmer and head and contains the drive shaft that connects the motor to the trimmer head.

Handle - The weed wacker is controlled by using one hand on the controls and one hand on the handle. The separation between the two grips allows for easy manipulation of the weed wacker.

Trimmer Head - The trimmer head is connected to the drive shaft inside the shaft. The trimmer head holds the loaded spool of string and rotates in order to cut the weeds or grass.

String - Weed Wackers use either use a two sided wedge or a four sided wedge. The wedge is a dimple mechanical device that splits the wood as it is pushed into the log.

Deflector - Weed Wackers use a deflector to protect the user from the rotating string as well as the debris created by the operation of the weed wacker. Deflectors also hold the string cutting blade. The string cutting blade is used to trim excess string when the trimmer head is rotating more than the desired length of weed wacker string.