27 CS-450
GUIDE BAR
• Clean before using.
- Clean the groove of the guide bar with a small
screwdriver.
- Clean oil holes with a wire.
• Reverse guide bar periodically.
• Check sprocket and the clutch and clean the bar
mount area before installation of the bar.
Replace either or both if worn.
SPROCKET
• A damaged sprocket will cause premature dam-
age or wear of saw chain.
- When the sprocket has worn out 0.5 mm
(0.020 in.) or more, replace it.
• Check sprocket when you install new chain.
Replace it if worn.
CYLINDER FINS
• Check periodically.
• Clogged ns will result in poor engine cooling.
• Remove dirt and dust from between ns to let
cooling air pass easily.
MUFFLER SPARK ARRESTOR
• Remove air cleaner cover and remove spark
plug lead.
• Remove spark arrestor screen cover and screen
from mufer body.
• Clean carbon deposits from mufer components.
• Replace screen if it is cracked, or has holes
burned through.
Inspect gasket, replace if damaged.
• Assemble components in reverse order.
NOTE
Carbon deposits in mufer will cause drop in
engine output. Spark arrestor screen must be
checked periodically.
AUTOMATIC OILER
• The discharge volume of the automatic oiler is
adjusted to 4 mL/min approximately at 7000 r/
min, prior to shipment from factory.
- To increase the delivery volume, turn the
adjusting screw counterclockwise.
When the screw touches stopper and stops,
this position indicates maximum discharge
volume. (13 to 14 mL/min at 7000 r/min)
- Do not turn the adjusting screw beyond the
maximum or minimum limit of volume adjust-
ment.
Worn : 0.5 mm (0.020 in.)
Groove
Oil hole
Cylinder ns
Spark arrestor screen
Mufer
Screen cover
Adjusting screw Decrease Increase
Clutch
(Sprocket)
Gasket