Husqvarna 445 II Operator's Manual page 35

To adjust the tension of the saw chain
WARNING: A saw chain with an incorrect
tension can come loose from the guide bar
and cause serious injury or death.
A saw chain becomes longer when you use it. Adjust the
saw chain regularly.
1. Loosen the bar nuts that hold the clutch cover/chain
brake. Use a wrench. (Fig. 123)
Note: Some models have only one bar nut.
2. Tighten the bar nuts by hand as tightly as you can.
3. Lift the front of the guide bar and turn the chain
tensioning screw. Use a wrench.
4. Tighten the saw chain until it is tight against the
guide bar but still can move easily. (Fig. 124)
5. Tighten the bar nuts using the wrench and lift the
front of the guide bar at the same time.
6. Make sure you can pull the saw chain around freely
by hand and that it does not hang from the guide
bar. (Fig. 125)
Product overview on page 19 for the
Note: Refer to
position of the chain tensioning screw on your product.
To do a check of the saw chain
lubrication
1. Start the product and let it operate at ¾ throttle. Hold
the bar approximately 20 cm/8 in above a surface of
light color.
2. If the saw chain lubrication is correct, you see a clear
line of oil on the surface after 1 minute. (Fig. 126)
3. If the saw chain lubrication does not operate
correctly, do a check of the guide bar. Refer to
a check of the guide bar on page 35 for
instructions. Speak to your servicing dealer if the
maintenance steps does not help.
To do a check of the spur sprocket
The clutch drum has a spur sprocket that is welded on
the clutch drum.
(Fig. 127)
• Regularly do a visual check of the degree of wear on
the spur sprocket. Replace the clutch drum with the
spur sprocket if there is too much wear.
To lubricate the needle bearing
1. Pull the front hand guard rearward to disengage the
chain brake.
2. Loosen the bar nuts and remove the clutch cover.
Note: Some models have only one bar nut.
1286 - 002 - 03.06.2020
3. Put the product on a stable surface with the clutch
drum up.
4. Lubricate the needle bearing with a grease gun. Use
engine oil or a bearing grease of high quality. (Fig.
128)
To examine the cutting equipment
1. Make sure that there are no cracks in rivets and links
and that no rivets are loose. Replace if it is
necessary. (Fig. 129)
2. Make sure that the saw chain is easy to bend.
Replace the saw chain if it is rigid.
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. (Fig.
130)
To do a check of the guide bar
1. Make sure that the oil channel is not blocked. Clean
if it is necessary. (Fig. 131)
2. Examine if there are burrs on the edges of the guide
bar. Remove the burrs using a file. (Fig. 132)
3. Clean the groove in the guide bar. (Fig. 133)
4. Examine the groove in the guide bar for wear.
Replace the guide bar if it is necessary. (Fig. 134)
5. Examine if the guide bar tip is rough or very worn.
(Fig. 135)
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. (Fig.
136)
7. Turn the guide bar daily to extend its life cycle. (Fig.
137)
To do
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.
Air cleaning system
™
AirInjection
removes dust and dirt before the particles are caught by
the air filter. AirInjection
and the engine.
(Fig. 138)
is a centrifugal air cleaning system that
™
extends the life of the air filter
35