If the cutting attachment still rotates after adjustment of
the idle speed adjustment screw (T), immediately stop
the engine and cease use, then contact the nearest
Hitachi Authorized Service Center.
Air ﬁ lter (Fig. 29)
The air ﬁ lter (27) must be cleaned from dust and dirt in order
○ 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.
Open the air ﬁ lter cover and remove the air ﬁ lter (27). Clean
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.
To put the air ﬁ lter cover back into place, hook it on the
upper tabs and then attach it.
Fuel ﬁ lter (Fig. 30)
Remove the fuel ﬁ lter (28) from the fuel tank, and replace it if
it is dirty.
A blocked fuel ﬁ lter (28) can prevent the supply of fuel and
cause a rotation malfunction of the engine.
Spark plug (Fig. 31)
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.
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.
Flexible drive shaft (Fig. 32)
Flexible drive shaft should be removed and lubricated with
good quality lithium grease every 20 hours. To remove the
ﬂ exible shaft, ﬁ rst remove screw (29), loosen bolt (30) and
remove the cutter case then pull the shaft out of the drive
shaft tube. Clean the shaft oﬀ and apply a generous coat of
lithium grease to it and insert if back into the drive shaft tube,
turn it unit it drops into place then install the cutter case,
install & tighten screw (29) and bolt (30).
Gear case (Fig. 33)
Check gear case or angle gear for grease level about every
50 hours of operation by removing the grease ﬁ ller plug on
the side of gear case.
If no grease can be seen on the ﬂ anks of the gears, ﬁ ll the
gear case with quality lithium based multipurpose grease up
to 3/4. Do not completely ﬁ ll the gear case.
○ Make sure to remove any dirt or grit when attaching the
plug to its original position.
○ Before attempting inspection or maintenance of the gear
case, make sure the case has cooled.
Semi-auto cutting head
Nylon line replacement
1. Remove the case (15) by ﬁ rmly pushing inward the
locking tabs with your thumbs as shown in Fig. 34.
2. After removing the case, take out the reel and discard
the remaining line.
3. Fold the new nylon line unevenly (approx. 10 cm) in half
as shown in picture.
Hook the U-shaped end of the nylon line into the groove
(31) on the center partition of the reel.
Wind both halves of the line on the reel in the same
direction, keeping each half of the line on its own side of
the partition. (Fig. 35)
4. Push each line into the stopper holes (32), leaving the
loose ends approx. 10 cm in length. (Fig. 36)
5. Insert both loose ends of the line through the cord guide
(33) when placing the reel in the case. (Fig. 37)
When placing a reel in the case, try to line up the stopper
holes (32) with the cord guide (33) for easier line release
6. Place the cover over the case so that the cap locking
tabs (35) on the cover meet the long holes (34) on the
case. Then push the case securely until it clicks into
place. (Fig. 38)
7. The initial cutting line length should be approx. 11–14 cm
and should be equal on both sides. (Fig. 39)
Blade (Fig. 40)
Wear protective gloves when handling or performing
maintenance on the blade.
○ Use a sharp blade. A dull blade is more likely to snag and
Replace the fastening nut if it is damaged and hard to
○ When replacing blade, purchase one recommended by
Hitachi, with a 25.4 mm (one inch) ﬁ tting hole.
○ In the case of a 3 tooth blade (36), it can be used on
○ 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.
When sharpening blade it is important to maintain an
original shape of radius at the base of the tooth to avoid
For long-term storage
Drain all fuel from the fuel tank. Start and let engine run until
it stops. Repair any damage which has resulted from use.
Clean the unit with a clean rag, or the use of high pressure
air hose. Put a few drops of two-cycle engine oil into the
cylinder through the spark plug hole, and spin the engine
over several times to distribute oil.
Cover the unit and store it in a dry area.
Below you will ﬁ nd some general maintenance instructions.
For further information please contact Hitachi Authorized