Fuel fi lter (Fig. 30)
Remove the fuel fi lter from the fuel tank, and replace it if it is
dirty.
NOTE
A blocked fuel fi lter can prevent the supply of fuel and
cause a rotation malfunction of the engine.
Spark plug (Fig. 31)
The spark plug condition is infl uenced by:
○ An incorrect carburetor setting.
○ Wrong fuel mixture (too much oil in the gasoline)
○ A dirty air fi lter.
○ Hard running conditions (such as cold weather).
These factors cause deposits on the spark plug electrodes,
which may result in malfunction and starting diffi culties. If
the engine is low on power, diffi cult to start or runs poorly at
idling speed, always check the spark plug fi rst.
If the spark plug is dirty, clean it and check the electrode
gap. Re-adjust if necessary. The correct gap is 0.6 mm. The
spark plug should be replaced after about 100 operation
hours or earlier if the electrodes are badly eroded.
NOTE
In some areas, local law requires using a resistor spark
plug to suppress ignition signals. If this machine was
originally equipped with resistor spark plug, use same
type of spark plug for replacement.
Gear case (Fig. 32)
Check gear case or angle gear for grease level about every
50 hours of operation by removing the grease fi ller plug on
the side of gear case.
If no grease can be seen on the fl anks of the gears, fi ll the
gear case with quality lithium based multipurpose grease up
to 3/4. Do not completely fi ll the gear case.
CAUTION
○ Make sure to remove any dirt or grit when attaching the
plug to its original position.
○ Before attempting inspection or maintenance of the gear
case, make sure the case has cooled.
Blade (Fig. 33)
WARNING
Wear protective gloves when handling or performing
maintenance on the blade.
○ Use a sharp blade. A dull blade is more likely to snag and
thrust.
Replace the fastening nut if it is damaged and hard to
tighten.
○ When replacing blade, purchase one recommended by
Hitachi, with a 25.4 mm (one inch) fi tting hole.
○ In the case of a 3 tooth blade (28), it can be used on
either side.
○ Use the correct blade for the type of work.
○ When replacing blades, use appropriate tools.
○ When cutting edges become dull, re-sharpen or fi le
as shown in the illustration. Incorrect sharpening may
cause excessive vibration.
○ Discard blades that are bent, warped, cracked, broken
or damaged in any way.
NOTE
When sharpening blade it is important to maintain an
original shape of radius at the base of the tooth to avoid
cracking.
Nylon head
Nylon line replacement
○ Remove the cutting body cap by pushing inward the
locking tabs on the side of the nylon head (Fig. 34).
Take out the spool (Fig. 35), hook the new nylon line
into the hole of the spool, then wind it around the spool
(Fig. 36).
When the nylon line has been wound around the spool,
temporarily fasten it in the opening of the spool at about
10 cm from the end. (Fig. 37) Then thread the nylon line
through the hole on the side of the nylon head and place
the cutting body cap in reverse order of the cap removal
(Fig. 38). Pull the right and left nylon lines until they are
secured about 15 - 16 cm from the end. (Fig. 39)
NOTE
Make sure that the right and left nylon lines are of equal
length since vibrations will otherwise increase.
Flexible shaft
Lubricate fl exible shaft from clutch housing side by removing
it every 20 hours of use.
For long-term storage
Drain all fuel from the fuel tank. Start and let engine run until
it stops. Repair any damage which has resulted from use.
Clean the unit with a clean rag, or the use of high pressure
air hose. Put a few drops of two-cycle engine oil into the
cylinder through the spark plug hole, and spin the engine
over several times to distribute oil.
Cover the unit and store it in a dry area.
Maintenance schedule
Below you will fi nd some general maintenance instructions.
For further information please contact Hitachi Authorized
Service Centers.
Daily maintenance
○ Clean the exterior of the unit.
○ Check that the harness is undamaged.
○ Check the cutting attachment guard for damage or
cracks. Change the guard in case of impacts or cracks.
○ Check that the cutting attachment is properly centered,
sharp, and without cracks. An off -center cutting
attachment induces heavy vibrations that may damage
the unit.
○ Check that the cutting attachment nut is suffi ciently
tightened.
○ Make sure that the blade cover is undamaged and that it
can be securely fi tted.
○ Check that nuts and screws are suffi ciently tightened.
○ Check that the unit is undamaged and free of defects.
Weekly maintenance
○ Check the starter, especially the cord.
○ Clean the exterior of the spark plug.
○ Remove the spark plug and check the electrode gap.
Adjust it to 0.6 mm, or change the spark plug.
○ Check that the angle gear is fi lled with grease up to 3/4.
○ Clean the air fi lter.
Monthly maintenance
○ Rinse the fuel tank with gasoline.
○ Clean the exterior of the carburetor and the space
around it.
○ Clean the fan and the space around it.
13
English