9
Fig. 20
NOTE
If element is hard due to excessive dirt build-up, replace it.
Spark plug (Fig. 21)
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. 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.
0.6 mm
Fig. 21
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.
Cutting blade (Fig. 22, 23)
The blades are installed to the blade guide with three to
fi
ve bolts
depending on blade length. Those bolts are tightened with a
clearance so that the blades can move smoothly.
Fig. 22
Fig. 23
When clearance is too small
The blades do not move properly and the sliding surfaces may seize.
When clearance is too large
The blades are poor in sharpness.
To adjust the blade clearance
1. Loosen the blade
fi
xing nuts.
2. Fully tighten the blade
fi
xing bolts and then loosen them approx.
1/2 turn.
3. With the bolts set at that position, tighten the blade
fi
xing nuts.
Be sure to replace blade guide
fi
xing bolts when they are loosened,
worn or damaged. Also be sure to replace damaged cutter blade.
NOTE
Properly lubricate the blade sliding surfaces with machine oil.
Gear case (Fig. 24)
Apply good quality lithium based grease through the grease
fi
ttings.
On some models, one of the grease
fi
ttings has been moved from
upper location to the bottom.
Fig. 24
NOTE
Lubrication should be applied at 50 hour intervals and more
frequently with heavy use.
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 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 the cord and return spring.
○
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 air intake at the starter is not clogged.
○
Check that the angle gear is
fi
lled with grease.
○
Clean the air
fi
lter.
000Book̲CH22EPA(S)̲Eng.indb 9
000Book̲CH22EPA(S)̲Eng.indb 9
2014/11/14 10:33:59
2014/11/14 10:33:59
