Husqvarna 120 Mark II Operator's Manual page 19

To do maintenance on the spark plug
CAUTION:
spark plug. Make sure that the
replacement is the same as the
manufacturer supplied part. An
incorrect spark plug can cause
damage to the product.
1. If the product is hard to start or operate,
examine the spark plug for unwanted
materials. To decrease the risk of
unwanted material on the spark plug
electrodes:
a) make sure that the idle speed is
correctly adjusted.
b) make sure that the fuel mixture is
correct.
c) make sure that the air filter is clean.
2. Clean the spark plug if it is dirty. Make sure
that the electrode gap is correct. (Fig. 72)
3. Replace the spark plug when it is
necessary.
To clean the air filter
1. Remove the air filter cover and remove the
air filter.
2. Clean the air filter with warm soap water.
Make sure that the air filter is dry before
you install it.
3. Replace the air filter if it is too dirty to fully
clean it. Always replace a damaged air
filter.
To sharpen the saw chain
The cutter
The cutting part of the saw chain is called the
cutter and consists of a cutting tooth (A) and
the depth gauge (B). The cutters cutting depth
is determined by the difference in height
between the two, the depth gauge setting (C).
(Fig. 73)
When you sharpen a cutting tooth there are
four important factors to remember:
• Filing angle.
(Fig. 74)
658 - 008 - 10.02.2020
Use the recommended
• Cutting angle.
(Fig. 75)
• File position.
(Fig. 76)
• Round file diameter.
(Fig. 77)
To sharpen the cutting teeth
Use a round file and a file gauge to sharpen
the cutting teeth. See
chain combinations on page 23 for
information on the recommended dimension of
the file and gauge for the saw chain installed
on your product.
1. Make sure that the saw chain is correctly
tensioned. A slack chain will move
sideways, making it more difficult to
sharpen correctly.
2. File all teeth on one side first. File the
cutting teeth from the inside face and
reduce the pressure on the return stroke.
3. Turn the product over and file the teeth on
the other side.
4. File all the teeth to the same length. When
the length of the cutting teeth is reduced to
4 mm (5/32") the saw chain is worn out and
must be replaced. (Fig. 78)
To adjust the depth gauge setting
Sharpen the cutting teeth before you adjust
the depth gauge setting. See
cutting teeth on page 19 . When you sharpen
the cutting tooth (A), the depth gauge setting
(C) will decrease. To maintain optimal cutting
performance, the depth gauge (B) has to be
filed down to achieve the recommended depth
gauge setting. See
chain combinations on page 23 to find the
correct depth gauge setting for your particular
chain.
(Fig. 79)
(Fig. 80)
Note:
This recommendation assumes that the
length of the cutting teeth is not reduced
excessively.
Saw chain filing and saw
To sharpen the
Saw chain filing and saw
19