WARNING
• Be sure to round off the front edge to reduce the
chance of kickback or tie-strap breakage.
Make sure every cutter has the same length and edge
angles as illustrated.
Cutter length
Guide Bar
•
Reverse the bar occasionally to prevent partial
wear.
10. Troubleshooting Guide
Case 1. Starting failure
WARNING
• Make sure the icing prevention system is not working.
Check fuel for wa-
ter or substandard
mixture.
Check for engine
flooding.
Check spark ignition.
Case 2. Lack of power/Poor acceleration/
Rough idling
Check fuel for wa-
ter or substandard
mixture.
Check air filter and
fuel filter for clog-
ging.
Check carburetor
for inadequate ad-
justment.
Filing angle
Side plate angle
Top plate cutting angle
Replace with prop-
er fuel.
Remove and dry the
spark plug.
Then pull the starter
again with no choke.
Replace with a new
plug.
Replace with prop-
er fuel.
Clean.
Readjust speed
needles.
•
The bar rail should always be square. Check for
wear of the bar rail. Apply a ruler to the bar and
the outside of a cutter. If a gap is observed be-
tween them, the rail is normal. Otherwise, the bar
rail is worn. Such a bar needs to be corrected or
replaced.
Ruler
Gap
No gap
WARNING
Chain tilts
• This saw is equipped with one of the following
low kickback bar/chain combinations:
Bar Size
Guide Bar
16
107-72811-200 138-32625-20(21BP-66E)
18
105-72830-201 136-32578-20(21BP-72E)
Case 3. Oil does not come out
Check oil for sub-
standard quality.
Check oil passage
and ports for clog-
ging.
If the unit seems to need further service, please con-
sult with an authorized service shop in your area.
HITACHI Part Number
Saw Chain
Replace.
Clean.
GB-15