A cutting attachment can injure while it continues to spin after
the engine is stopped or power control is released. When the
unit is turned oﬀ , make sure the cutting attachment has stopped
before the unit is set down.
Automatically feeds more nylon cutting line when it is tapped at low
rpm (not greater than 4500 rpm).
MAINTENANCE, REPLACEMENT OR REPAIR OF THE EMISSION
CONTROL DEVICES AND SYSTEMS MAY BE PERFORMED
BY ANY NON-ROAD ENGINE REPAIR ESTABLISHMENT OR
Carburetor adjustment (Fig. 29)
○ The cutting attachment may be spinning during carburetor
○ Never start the engine without the complete clutch cover and
tube 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 basically 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 ﬁ lter is clean. When the idle speed is correct, the
cutting attachment will not rotate. If adjustment is required, close
(clockwise) the T-screw, with the engine running, until the cutting
attachment starts to rotate. Open (counter-clockwise) the screw
until the cutting attachment stops. You have reached the correct idle
speed when the engine runs smoothly in all positions well below the
rpm when the cutting attachment starts to rotate.
If the cutting attachment still rotates after idle speed adjustment,
contact Hitachi Authorized Service Centers.
○ Standard Idle rpm is 2800-3200 rpm.
When the engine is idling the cutting attachment must under no
Air ﬁ lter (Fig. 30)
The air ﬁ lter must be cleaned from dust and dirt in order to avoid:
○ Carburetor malfunctions
○ Starting problems
○ Engine power reduction
○ Unnecessary wear on the engine parts
○ Abnormal fuel consumption
Clean the air ﬁ lter daily or more often if working in exceptionally
Cleaning the air ﬁ lter
Open the air ﬁ lter cover and the ﬁ lter (28). Rinse it in warm soap
suds. Check that the ﬁ lter is dry before reassembly. An air ﬁ lter
that has been used for some time cannot be cleaned completely.
Therefore, it must regularly be replaced with a new one. A damaged
ﬁ lter must always be replaced.
Fuel ﬁ lter (Fig. 31)
Drain all fuel from fuel tank and pull fuel ﬁ lter line from tank. Pull
ﬁ lter element out of holder assembly and rinse element in warm
water with detergent.
Rinse thoroughly until all traces of detergent are eliminated.
Squeeze, do not wring, away excess water and allow element to air
If element is hard due to excessive dirt buildup, replace it.
Spark plug (Fig. 32)
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.