Hitachi CG31EBS - Инструкция по эксплуатации - Страница 13

12

English

Carburetor

adjustment

 (

Fig.

29

)

WARNING

○

  The cutting attachment may be spinning during carburetor 

adjustments.

○

  Never star t the engine without the complete clutch cover and 

tube assembled! Other wise 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 factor y, the carburetor is basically adjusted. A fur ther 
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 star ts 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 star ts to rotate.
If the cutting attachment still rotates after idle speed adjustment, 
contact your Hitachi dealer.

NOTE

Standard Idle rpm is 2200 –2800 rpm.

WARNING

When the engine is idling the cutting attachment must under no 
circumstances rotate.

Air

 fi 

lter

 (

Fig.

30

)

The air 

fi

 lter must be cleaned from dust and dir t in order to avoid:

○

 Carburetor 

malfunctions

○

 Star ting 

problems

○

  Engine power reduction

○

  Unnecessar y wear on the engine par ts

○

  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 dr y 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 
dr y.

NOTE

If element is hard due to excessive dir t buildup, replace it.

Spark

plug

 (

Fig.

32

)

The spark plug condition is in

fl

 uenced by:

○

  An incorrect carburetor setting

○

  Wrong fuel mixture (too much oil in the gasoline)

○

  A dir ty 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 star ting di

ffi

  culties. If the engine 

is  low  on  power,  di

ffi

  cult  to  star t  or  runs  poorly  at  idling  speed, 

always check the spark plug 

fi

 rst. If the spark plug is dir ty, clean it 

and check the electrode gap. Re-adjust if necessar y. 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.

Mu

ffl

er

 (

Fig.

33

)

Remove the mu

ffl

  er and clean out any excess carbon from the 

exhaust por t or mu

ffl

  er inlet ever y 100 hours of operation.

Cylinder

 (

Engine

cooling

) (

Fig.

34

)

The engine is air cooled, and air must circulate freely around engine 
and over cooling 

fi

 ns on cylinder head to prevent overheating.

Ever y 100 operating hours, or once a year (more often if conditions 
require), clean 

fi

 ns and external sur faces of engine of dust, dir t and 

oil deposits which can contribute to improper cooling.

NOTE

Do not operate engine with engine shroud or mu

ffl

  er  guard 

removed as this will cause overheating and engine damage.

Angle

transmission

 (

Fig.

35

)

Check angle transmission or angle gear for grease level about ever y 
50 hours of operation by removing the grease 

fi

 ller plug on the side 

of angle transmission.
If  no  grease  can  be  seen  on  the 

fl

 anks of the gears, 

fi

 ll  the 

transmission with quality lithium based multipurpose grease up to 
3/4. Do not completely 

fi

 ll the transmission.

Blade

WARNING

  Wear protective gloves when handling or per forming 

maintenance on the blade. (

Fig.

36

)

○

  Use a sharp blade. A dull blade is more likely to snag and thrust. 

Replace the fastening nut if it is damaged and hard to tighten.

○

  When replacing blade, purchase one recommended by Hitachi, 

with a 25.4 mm (one inch) 

fi

 tting hole.

○

  When installing a saw blade, always face the stamped side up. 

In the case of a 3 tooth blade, it can be used on either side.

○

  Use the correct blade for the type of work.

○

  When replacing blades, use appropriate tools.

○

  When cutting edges become dull, re-sharpen or 

fi

 le as shown 

in the illustration. Incorrect sharpening may cause excessive 
vibration.

○

  Discard blades that are bent, warped, cracked, broken or 

damaged in any way.

NOTE

When  sharpening  blade  it  is  impor tant  to  maintain  an  original 
shape of radius at the base of the tooth to avoid cracking.

Nylon

head

Nylon line replacement

○

  Remove the cutting body cap by pushing inward the locking 

tabs on  the side of the nylon head (

Fig.

37

). Take out the spool 

(

Fig.

38

), hook the new nylon line into the hole of the spool, then 

wind it around the spool in two stages (

Fig.

39

).

When the nylon line has been wound around the spool, 
temporarily fasten it in the opening of the spool at about 10 cm 
from the end. (

Fig.

40

) Then thread the nylon line through the 

hole on the side of the nylon head and place the cutting body 
cap in reverse order of the cap removal. Pull the right and left 
nylon lines until they are secured about 15 

–

 16 cm from the end. 

(

Fig.

42

)

NOTE

○

  The nylon head is designed for nylon lines with an outer 

diameter of 2.5 mm. Do not use nylon lines with a di

ff

 erent outer 

diameter.

○

  Make sure that the right and left nylon lines are of equal length 

since vibrations will other wise increase.

Maintenance

schedule

Below you will 

fi

 nd some general maintenance instructions. For 

fur ther information please contact your Hitachi dealer.

Daily

maintenance

○

  Clean the exterior of the unit.

○

  Check that the harness is undamaged.

○

  Check the blade guard for damage or cracks. Change the guard 

in case of impacts or cracks.

000Book̲CG31EBS̲EE.indb   12

000Book̲CG31EBS̲EE.indb   12

2009/10/15   9:13:39

2009/10/15   9:13:39