Maintenance - Hitachi CG25EJ Mode D'emploi

5. Maintenance

MAINTENANCE, REPLACEMENT, OR REPAIR
OF THE EMISSION CONTROL DEVICES AND
SYSTEMS MAY BE PERFORMED BY ANY
NON-ROAD ENGINE REPAIR
ESTABLISHMENT OR INDIVIDUAL.
Carburetor adjustment (Fig. 3-1)
WARNING!
The cutting attachment may be spinning
during carburetor adjustments.
WARNING!
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 filter 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 your service workshop.
NOTE!
Standard Idle rpm is 2500~3000 rpm.
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
Fig. 3-3
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 cutting
attachment must under no circumstances
rotate.
Air filter (Fig. 3-2)
The air filter 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.
Fig.3-2
Clean the air filter daily or more often if working
in exceptionally dusty areas.
Cleaning the air filter
Remove the air filter cover and the filter (1). Rinse
it in warm soap suds. Check that the filter is dry
before reassembly. An air filter that has been used
for some time cannot be cleaned completely.
Therefore, it must regularly be replaced with a new
one. A damaged filter must always be replaced.
Fuel filter (Fig. 3-2B)
Drain all fuel from fuel tank and pull fuel filter line
from tank. Pull filter 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 dry.
NOTE!
If element is hard due to excessive dirt buildup,
replace it.
Spark plug (Fig. 3-3)
The spark plug condition is influenced by:
An incorrect carburetor setting.
Wrong fuel mixture (too much oil in the gasoline)
A dirty air filter.
Hard running conditions (such as cold weather).
These factors cause deposits on the spark plug
electrodes, which may result in malfunction and
starting difficulties. If the engine is low on power,
difficult to start or runs poorly at idling speed,
always check the spark plug first. 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.
G
B
Fig.3-1
Fig. 3-2B
GB-13