Troy-Bilt TB304BC Operator's Manual page 20

NOTE: If too little line is left protruding, it could retract inside the
cutting head.
Removing Old Trimming Line and Obstructions
1. When the trimming line runs out, the last piece should
automatically eject from the cutting head. If it does not, push the
bump knob down and pull the remaining line out of the cutting
head.
2. If the line will not come out or the cutting head is otherwise
obstructed:
a. Firmly press a tab on the cutting head with your thumb (Fig. 31).
DO NOT press the tab with a screwdriver or other object.
b. Continue pressing the tab. Insert a flat-head screwdriver into
the gap between the outer spool and tab (Fig. 31).
c. Gently tilt the screwdriver to unlock the tab from the hole (Fig. 32).
d. Repeat the previous steps for the other tab.
e. Remove the spool cover (Fig. 32). DO NOT attempt to remove
any other parts of the cutting head.
f. Remove any old trimming line and/or obstructions.
g. Use a clean cloth to clean the inner reel, outer spool and spool
cover (Fig. 32).
h. Align the tabs on the spool cover with the holes on the outer
spool (Fig. 32). Push the spool cover onto the outer spool until
the tabs securely snap into the holes.
MAINTAINING THE BLADE
WARNING:
Do not sharpen the blade. Sharpening the
blade can cause the blade tip to break off while in use.
This can result in severe personal injury.
The blade has a second cutting edge. If the blade becomes dull,
remove the blade, turn it upside down and reinstall the blade. If both
sides are dull, replace the blade. Refer to Removing the Blade and
Installing the Blade in the Assembly section.
Bump Knob
Outer Spool
Tab
Hole
20
Fig. 30
Gap
Tab
Fig. 31
Spool Cover
Inner Reel
Outer Spool
Fig. 32