Hitachi Koki CH 27EPA (S) Instrucciones De Manejo página 9

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.
NOTE
Standard Idle rpm is 3000 min
WARNING
When the engine is idling the cutting attachment must under no
circumstances rotate.
Air fi lter (Fig. 18)
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
dusty areas.
Cleaning the air fi lter
Remove the air fi lter cover and the fi lter (19). 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. 19)
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 dry.
NOTE
If element is hard due to excessive dirt build-up, replace it.
Spark plug (Fig. 20)
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.
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. 21, 22)
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.
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.
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NOTE
Properly lubricate the blade sliding surfaces with machine oil.
Gear case (Fig. 23)
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.
NOTE
Lubrication should be applied about 5 g at 20 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
○ Check to ascertain that the fuel is not leaking.
○ 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 suffi 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 suffi 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.
Monthly maintenance
○ Rinse the fuel tank with gasoline, and clean fuel fi lter.
○ Clean the exterior of the carburetor and the space around it.
Quarterly maintenance
○ Clean the cooling fi ns on the cylinder.
○ Clean the fan and the space around it.
○ Clean the muffl er of carbon.
CAUTION
Cleaning of cylinder fi ns, fan and muffl er shall be done by a
Hitachi Authorized Service Center.
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