Drilling (Fig. 2-5)
WARNING!
Do not touch the bit when running the
engine to avoid unexpected accident. Be
sure to turn off the ignition switch before
touching it.
1. Hold the handle firmly with both hands so
that you may not be swung by the unit.
2. Locate the edge of bit right on the spot to
dig, and then drive the bit.
This is an easy job thanks to the built-in
centrifugal clutch.
3. Stop the engine and inspect the unit if
abnormal vibration or noise is generated.
4. Long operation of the unit may tire you. Try
to take a break from time to time.
Stopping (Fig. 2-6)
Decrease engine speed, and push ignition
switch to stop position.
Fig. 2-5
5. Maintenance
MAINTENANCE. REPLACEMENT, OR RE-
PAIR OF THE EMISSION CONTROL DE-
VICES AND SYSTEM MAY BE PERFORMED
BY ANY NONROAD ENGINE REPAIR ES-
TABLISHMENT OR INDIVIDUAL.
Carburetor adjustment (Fig. 3-1)
WARNING!
The bit may be spinning during carburetor
adjustments.
WARNING!
Never start the engine without the complete
clutch cover and gear case assembled!
Otherwise the clutch can come loose and
cause personal injuries.
In the carburetor, fuel is mixed with air. When
the engine is test run at the factory, the
carburetor is adjusted. A further adjustment may
be required, according to climate and altitude.
The carburetor has one adjustment possibility:
T = Idle speed adjustment screw.
Idle speed adjustment (T)
Check that the air filter is clean. When the idle
speed is correct, the bit will not rotate. If
adjustment is required, close (clockwise) the T-
screw, with the engine running, until the bit
starts to rotate. Open (counter-clockwise) the
screw until the bit stops. You have reached the
correct idle speed when the engine runs
smoothly in all positions well below the rpm
when the bit starts to rotate.
If the bit still rotates after idle speed adjustment,
contact HITACHI dealer.
NOTE!
Standard Idle rpm is 2500~3000 rpm.
Fig. 2-6
NOTE!
Some models sold areas with strict exhaust
emission regulation do not have high and low
speed carburetor adjustments. Such
adjustments may allow the engine to be
operated outside of their emission compliance
limits. For these models, the only carburetor
adjustment is idle speed.
For models that equipped with low and high
speed adjustments; carburetors are pre set at
the factory Minor adjustments may optimize
performance based on climate, altitude, etc.
Never turn the adjustment screws in increments
greater than 90 degrees, as engine damage
can result from incorrect adjustment If you are
not familiar with type of adjustment-assistance
HITACHI dealer.
WARNING!
When the engine is idling the bit must under
no circumstances rotate.
G
B
Fig. 3-1
GB-7