Stihl 26 - Checking and Replacing Chain Sprocket

Chain Pitch Minimum
type groove
depth
Rapid 0.325" 6.0 mm (0.24")
Picco 3/8" 6.0 mm (0.24")
Rapid 3/8" 6.0 mm (0.24")
If groove depth is less than specified:
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The drive link tangs will otherwise scrape
along the bottom of the groove -
the cutters and tie straps will not ride on
the bar rails.
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or sooner if the wear marks on the sprok-
ket are deeper than approx.
0.5 mm (
1
/
64
") since this would reduce
the life of the chain.
Check wear marks:
Left: on webs of rim sprockets -
Right: on teeth of spur sprockets.
You can use gauge* 0000 893 4101
to check the depth of the wear marks on
spur and rim sprockets.
It is best to use two chains in rotation
with one sprocket.
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•
Remove chain sprocket cover,
chain and guide bar.
•
Disengage the chain brake:
Pull hand guard toward front handle.
* Special accessory
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Use a screwdriver to
•
remove the E-clip.
•
Take off the washer and
•
rim sprocket.
•
Examine splines on clutch drum -
if wear marks are severe, fit a new
clutch drum:
Pull clutch drum and needle cage
off the crankshaft - clean the
crankshaft stub and needle cage,
and lubricate with STIHL grease
(tube 0781 120 1111).
Reassemble with new rim sprocket
and new clutch drum, if necessary -
•
fit rim sprocket with cavities facing
outward -
refit washer and E-clip on the crankshaft.
Use only original STIHL clutch drums to
ensure correct operation
of the chain brake.
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