Troubleshooting - Husqvarna 120 Operator's Manual

a check of the guide bar on page 24 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. 121)
• 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 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. 122)
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.
123)
To do a check of the guide bar
1. Make sure that the oil channel is not blocked. Clean
if it is necessary. (Fig. 124)
2. Examine if there are burrs on the edges of the guide
bar. Remove the burrs using a file. (Fig. 125)
3. Clean the groove in the guide bar. (Fig. 126)
4. Examine the groove in the guide bar for wear.
Replace the guide bar if it is necessary. (Fig. 127)
5. Examine if the guide bar tip is rough or very worn.
(Fig. 128)
The engine does not start
Product part to examine
Starter pawls
24
6. Make sure that the bar tip sprocket turns freely and
7. Turn the guide bar daily to extend its life cycle. (Fig.
To do maintenance on the fuel tank
and the chain oil tank
•
•
To clean the cooling system
The cooling system keeps the engine temperature
down. The cooling system includes the air intake on the
starter (A), the air guide plate (B), the pawls on the
flywheel (C), the cooling fins on the cylinder (D), and the
cylinder cover (E).
(Fig. 131)
1. Clean the cooling system with a brush weekly or
2. Make sure that the cooling system is not dirty or

Troubleshooting

Possible cause
The starter pawls are blocked.
that the lubricating hole in the bar tip sprocket is not
blocked. Clean and lubricate if it is necessary. (Fig.
129)
130)
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.
more frequently if it is necessary.
blocked.
CAUTION: A dirty or blocked cooling
system can make the product too hot,
which can cause damage to the product.
Action
Adjust or replace the starter pawls.
Clean around the pawls.
Speak to an approved service work-
shop.
930 - 003 - 06.03.2019