Husqvarna 439 Operator's Manual page 31

3. Compare the saw chain with a new saw chain to
examine if the rivets and links are worn.
4. Replace the saw chain when the longest part of the
cutting tooth is less than 4 mm/0.16 in. Also replace
the saw chain if there are cracks on the cutters.
To do a check of the guide bar
1. Make sure that the oil channel is not blocked. Clean
if it is necessary.
2. Examine if there are burrs on the edges of the guide
bar. Remove the burrs using a file.
3. Clean the groove in the guide bar.
4. Examine the groove in the guide bar for wear.
Replace the guide bar if it is necessary.
823 - 002 - 08.11.2018
5. Examine if the guide bar tip is rough or very worn.
6. Make sure that the bar tip sprocket turns freely and
that the lubricating hole in the bar tip sprocket is not
blocked. Clean and lubricate if it is necessary.
7. Turn the guide bar daily to extend its life cycle.
To do maintenance on the fuel tank
and the chain oil tank
• Drain and clean the fuel tank and the chain oil tank
regularly.
• Replace the fuel filter yearly or more frequently if
necessary.
CAUTION: Contamination in the tanks
causes malfunction.
To adjust the oil flow
WARNING: Stop the engine before you
make adjustments to the oil pump.
1. Turn the adjustment screw for the oil pump. Use a
screwdriver or combination wrench.
a) Turn the adjustment screw clockwise to decrease
the chain oil flow.
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