Stihl BT 121 Instruction Manual page 23

The following intervals apply to normal operating conditions only. If your daily work-
ing time is longer or operating conditions are difficult (very dusty work area, etc.),
shorten the specified intervals accordingly.
Drilling spindle
Auger
Safety labels
1)
STIHL recommends a STIHL servicing dealer.
2)
not in all versions, market-specific
BT 121
Clean
Check
Replace
Replace
X
X
English
X
X
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