48 49

50

51

Fig. 39

39.Top plate

40.Working corner

41.Side plate

42.Gullet

43.Heel

44.Chassis

45.Rivet hole

46.Toe

47.Depth gauge

48.Correct angle on top plate (degree of angle depends on chain type)

49.Slightly protruding “hook” or point (curve on non-chisel chain)

50.Top of depth gauge at correct height below top plate

51.Front of depth gauge rounded off

LOWERING DEPTH GAUGES WITH A FILE

1) If you sharpen your cutters with a file holder, check and lower the depth.

2) Check depth gauges every third sharpening.

3) Place depth gauge tool on cutter. If depth gauge projects, file it level with the top of the tool. Always file from the inside of the chain toward an outside cutter. (Fig. 40)

Fig. 40

4)Round off front corner to maintain original shape of depth gauge after using depth gauge tool. Always follow the recommended depth gauge setting found in the maintenance or operator manual for your saw. (Fig. 41)

Fig. 41

GENERAL INSTRUCTIONS FOR FILING CUTTERS

File (52) cutter on one side of the chain from the inside out. File on forward stroke only. (Fig. 42)

52

5252

Fig. 42

5)Keep all cutters the same length. (Fig. 43)

Fig. 43

6)File enough to remove any damage to cutting edges (side plate (53) and top plate (54)) of cutter. (Fig. 44)

5354

Fig. 44

SHARPENING ANGLES FOR SHARPENING SAW CHAIN

1. Part Number

91VG

2. Pitch

3/8"

3. Depth Gauge Setting

0.025"

 

 

4. Side Plate Filing Angle

80°

 

 

5. Top Plate Angle

30°

 

 

6. File Guide Angle

90°

 

 

Maintenance schedule

Below you will find some general maintenance instructions. For further information please contact HITACHI dealer.

Daily maintenance

○ Clean the exterior of the unit. ○ Clean the chain oil filter port.

○ Clean the groove and oil filter port in the guide bar. ○ Clean the side case of saw dust.

○ Check that the saw chain is sharp.

○ Check that the bar nuts are sufficiently tightened.

○ Make sure that the chain transport guard is undamaged and that it can be securely fitted.

○ Check that nuts and screws are sufficiently tightened.

○ Check the tip of the bar. Please exchange it for the new one when it is worn out.

○ Check the band of chain brake. Please exchange it for the new one when it is worn out.

Weekly maintenance

○ Check the starter, especially 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.

○ Clean the cooling fins on the cylinder and check that the air intake at the starter is not clogged.

○ Clean the air filter.

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