WARNING: Always protect your hands by wearing heavy gloves when performing any maintenance on the line-cutting blade.
Loosen the two screws and remove the line-cutting blade from the guard.
Q-1 Screws
Q-2 Line-cutting blade
2. Secure the blade in a vise
3. Carefully file the cutting edges of the blade with a fine tooth file or sharpening stone, being careful to maintain the original cutting-edge angle.
4. Replace the blade onto the guard and secure it in place with the two screws
Possible cause: The line-cutting blade on the edge of the guard has become dull.