9
English
Spark
plug
(
Fig.
11
)
The spark plug condition is in
fl
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 di
ffi
culties. If the engine
is low on power, di
ffi
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. Readjust 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 the same type of spark
plug for replacement.
Cutter
blade
(
Fig.
12,
13
)
The blades are installed to the cutter guide with the four or
fi
ve
bolts. Those bolts are tightened with a clearance so that the cutters
can move smoothly.
When
clearance
is
too
small
The cutters do not move properly and the sliding surfaces may
seize.
When
clearance
is
too
large
The cutters are poor in sharpness.
To
adjust
the
cutter
clearance
1. Loosen the cutter
fi
xing nuts.
2. Fully tighten the cutter
fi
xing bolts and then loosen them approx.
1/2 turn.
3. With the bolts set at that position, tighten the cutter
fi
xing nuts.
Be sure to replace cutter guide
fi
xing bolts when they are loosened,
worn or damaged. Also be sure to replace damaged cutter blade.
NOTE
Properly lubricate the cutter sliding surfaces with machine oil.
Gear
case
(
Fig.
14
)
Apply a good quality lithium based grease through the grease
fi
tting
until a small amount comes out between the cutter blades and the
gear case.
NOTE
Lubrication should be applied at 20 hour intervals and more
frequently with heavy use.
Fuel
fi
lter
(
Fig.
15
)
Remove the fuel
fi
lter from the fuel tank and thoroughly wash it in
solvent. After that, push the
fi
lter into the tank completely.
NOTE
If
the
fi
lter is hard due to dust and dirt, replace it.
Cleaning
the
cylinder
fi
ns
(
Fig.
16
)
When leaves get caught between cylinder
fi
ns (8), the engine may
overheat, resulting in lower output. To avoid this, always keep
cylinder
fi
ns and fan case clean.
Every 100 operating hours, or once a year (more often if conditions
require), clean
fi
ns and external surfaces of engine of dust, dirt and
oil deposits which can contribute to improper cooling.
Cleaning
the
mu
ffl
er
(
Fig.
17
)
Remove the mu
ffl
er and spark arrestor (if so equipped), and clean
out any excess carbon from the exhaust port or mu
ffl
er inlet every
100 hours of operation.
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 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 your Hitachi dealer.
Daily
maintenance
○
Clean the exterior of the hedge trimmer.
○
Check the blade guard for damage or cracks. Change the guard
in case of impacts or cracks.
○
Check that the blade is sharp, and without cracks.
○
Check that the blade nut is su
ffi
ciently tightened.
○
Make sure that the blade transport guard is undamaged and
that it can be securely
fi
tted.
○
Check that nuts and screws are su
ffi
ciently tightened.
Weekly
maintenance
○
Check the starter, especially cord and return spring.
○
Clean the exterior of the spark plug.
○
Remove it and check the electrode gap. Adjust it to 0.6 mm, or
change the spark plug.
○
Clean the cooling
fi
ns on the cylinder and check that the air
intake at the starter is not clogged.
○
Check gear case is
fi
lled with grease.
○
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.
000Book̲CH50EA3̲WE̲NE.indb 9
000Book̲CH50EA3̲WE̲NE.indb 9
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2009/10/27 15:38:08
