How to Replace Lines on a Dual Feed Grass Trimmer
- 1). Disconnect the spark plug wire from the spark plug on gasoline-powered trimmers. On electric models, disconnect the electrical cord from the power outlet, or remove the battery on battery-powered units.
- 2). Turn the trimmer upside down, with the cutting head facing upward. Remove any long weeds or grasses that may be wrapped around the cutting head or drive shaft.
- 3). Push in on the large knob in the center of the head and rotate the spool counterclockwise. Once the spool is loose, you can pull it out of the head.
For models with a spool cover, press on the tabs on opposite sides of the cover and lift the cover off. Then, pull out the spool. - 4). Remove any loose sections of string. Insert the end of a new line from a reel of new string into the hole in the center of the two winding sections of the spool and begin winding in the direction shown by the arrow on the spool. Keep winding until this half of the spool is full. Cut the line from the reel with a utility knife, while holding the line around the spool in place.
- 5). Wrap a piece of electrical tape around the wound string, to hold it fast so you can wind new line around the second spool.
- 6). Repeat Step 4 with new line on the other spool.
- 7). Remove the electrical tape, while holding both spools of line with your hand. Place the spool over the trimmer head and insert the end of each line into the corresponding hole in the trimmer head. Then, fit the spool into the head and pull the lines taut through the holes in the trimmer head. Rotate the spool clockwise (or replace the spool cover).
- 8). Reconnect the spark plug wire, electrical cord or battery, and test the trimmer.
Source...