Hitachi RB24E - Maintenance; Carburetor and Idle Speed Adjustment; Spark Plug Maintenance

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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. 11)
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 lter is clean. If adjustment is required, turn
IDLE speed Adjustment Screw (T) close (clockwise) to increase
engine speed, open (counterclockwise) to decrease engine speed.
Standard Idle rpm is 2800-3200rpm.
CAUTION
The above adjusting procedure must be followed when adjustment
is MADE or DAMAGE to engine will occur because of the incorrect
condition.
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.
RECOMMENDATION:
CARBURETOR ADJUSTMENT NEEDS THE SKILL OF
EXPERIENCED OR WELL TRAINED PEOPLE, OR IS
RECOMMENDED TO TAKE THE UNIT TO Hitachi Authorized
Service Centers.
Air lter (Fig. 12)
The air 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.
Remove the air cleaner cover by pushing and pulling back the tab
on the top. (Fig. 12)
Cleaning the air lter
Clean the cleaner element every day or every 8 hours of operation.
More frequent cleaning is recommended under very dusty
conditions. Wash the element in liquid detergent and water.
Squeeze the element to remove the dirt. Press the element in a dry
rag until it is completely dry. Saturate the element in 2 cycle oil.
Squeeze the element to distribute the oil completely and to remove
any excess oil. Replace the element and install the cover. (Fig. 13)
An air lter that has been used for some time cannot be cleaned
completely. Therefore, it must regularly be replaced with a new
one. A damaged lter must always be replaced.
Fuel lter (Fig. 14)
Drain all fuel from fuel tank and pull fuel lter line from tank. Pull
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 dry.
NOTE
If element is hard due to excessive dirt buildup, replace it.
Spark plug (Fig. 15)
The spark plug condition is inuenced by:
• An incorrect carburetor setting.
• Wrong fuel mixture (too much oil in the gasoline)
• A dirty air lter.
• Hard running conditions (such as cold weather).
These factors cause deposits on the spark plug electrodes, which
may result in malfunction and starting difculties. If the engine
is low on power, difcult to start or runs poorly at idling speed,
always check the spark plug 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.
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.
Maintenance schedule
Below you will nd some general maintenance instructions. For
further information please contact Hitachi Authorized Service
Centers.
Daily maintenance
• Clean the exterior of the unit.
• Check that the air intake at the dust cover is not clogged.
• Check the dust cover for damage or cracks. Change the cover in
case of impacts or cracks.
• Check that nuts and screws are sufciently tightened.
Weekly maintenance
• Check the starter, especially cord.
• 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 air lter.
Monthly maintenance
• Rinse the fuel tank with gasoline, and clean fuel lter.
• Clean the exterior of the carburetor and the space around it.
Quarterly maintenance
• Clean the cooling ns on the cylinder.
• Clean the fan and the space around it.
• Clean the mufer of carbon.
CAUTION
Cleaning of cylinder ns, fan and mufer shall be done by a
Hitachi Authorized Service Centers.
NOTE
When ordering the parts to your nearest dealer, please use
the item No. showing on the parts breakdown section in this
instruction.