Hitachi Koki CG 25EUS L Manual

[ NEW FEATURES ]
Small OHV Four-stroke Engine
Lightest weight in its Class
Smallest engine in its Class
PRODUCT NAME
Hitachi Engine Grass Trimmer
Models CG 25EUS (L)
CG 25EUS
The newly released CG 25EUS Engine Grass Trimmer is Hitachi Koki group first tool equipped with a small four-
cycle engine. There is now a growing need for tools equipped with a small, low-exhaust four-cycle engine as
environmentally friendly products.
With the new Model CG 25EUS, we aim to enhance the market share of Hitachi’s engine grass trimmer series.
LIST Nos.
CG 25EUS: E071
May. 2010
Cutting grass:
•Cutting grass in fields
•Cutting undergrowth in orchards
•Cutting other general kinds of grass
MARKETING OBJECTIVE
APPLICATIONS
SELLING POINTS
Sales Division
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT.
C
CG 25EUS (L)

REMARK:
• For more information about HANDLING INSTRUCTIONS, visit our website at:
http://www.hitachi-koki.com/manual_view_export/
• Throughout this TECHNICAL DATA AND SERVICE MANUAL, a symbol(s) is(are) used in the place of
company name(s) and model name(s) of our competitor(s). The symbol(s) utilized here is(are) as follows:
Competitors
Symbols Utilized
Company Name Model Name
A HONDA UMK 425LE
B Makita EM 4251

CONTENTS
Page
SELLING POINTS -------------------------------------------------------------------------------------------------------------1
SPECIFICATIONS -------------------------------------------------------------------------------------------------------------2
COMPARISON WITH SIMILAR PRODUCTS ---------------------------------------------------------------------------3
PRECAUTIONS ON SALES PROMOTION -----------------------------------------------------------------------------4
1. Safety Instructions ----------------------------------------------------------------------------------------------- 4
2. Specific Instructions for Customers -------------------------------------------------------------------------- 5
TROUBLESHOOTING GUIDE --------------------------------------------------------------------------------------------- 6
REPAIR GUIDE -----------------------------------------------------------------------------------------------------------------8
1. Precautions on Maintenance, Inspection and Repair --------------------------------------------------- 8
2. Inspection Criteria for Each Section and Consumable Parts ----------------------------------------- 8
Assembly Diagram for CG 25EUS

-1-
Small OHV Four-stroke Engine
The Model CG 25EUS comes equipped with the first small four-cycle engine among grass trimmers
produced by the Hitachi Koki group.
Thanks to the use of this four-cycle engine with low gas emissions, the Model CG 25EUS complies with
secondary exhaust regulations in Europe and the USA.
Compared with models equipped with a two-cycle engine, the Model CG 25EUS reduces noise by 3 dB and
engine oil consumption by 80 percent.
•Low gas emissions
Exhaust regulation
(g/kWh) CG 25EUS (L)
THC + NOx 50 or less 32
•Comparison of engines
HITACHI
CG 25EUS (L)
(four-cycle engine)
HITACHI
CG 24EKS
(two-cycle engine)
Engine oil consumption (mL/h) 3.0 15.0
Idling (dB) 70.6 76.3
Racing (dB) 90.6 96.8
Noise level at
operator's ear
Equivalent
mean
(dB) 87.0 94.0
Lightest Weight in its Class
The Model CG 25EUS features the lightest weight in its class of engine grass trimmers.
HITACHI
CG 25EUS (L) AB
Dry weight (kg)
(catalog data/
measured data)
5.0/5.0 5.2/5.46 5.2/–
Smallest Engine in its Class
The Model CG 25EUS features the smallest engine in its class of engine grass trimmers.
HITACHI
CG 25EUS (L) AB
Engine volume (L) 4.7 4.9 4.8
SELLING POINTS

-2-
Model CG 25EUS (L) CG 25EUS
Engine type Forced air-cooling, four-cycle OHV engine (type F25)
Engine displacement 25 mL
Cylinder size
(inner diameter x stroke) Ф35 x 26 mm
Max. power output 0.81 kW (1.1 hp) / 7,500 min-1
Max. rpm speed 9,500 to 11,500 min-1
Idling speed 2,500 to 3,500 min-1
Applicable fuel Unleaded regular gasoline for automobiles
Applicable engine oil SAE10W-30 oil of API SF or higher class
(Four-stroke engine oil for automobiles)
Fuel tank capacity Other than U.S.A.: 550 mL U.S.A.: 500 mL
Engine oil tank capacity 80 mL
Starting method Recoil starter
Ignition Fly-wheel magnet type
Spark plug NGK CMR-5H
Carburetor Diaphragm (with primer pump)
Stop switch Rocker type switch
Throttle lever Trigger type
Carrying Shoulder carrying (single strap)
Handle Loop Handle Bike Handle
Cutter blades Nylon cutter
Blade rotation Counterclockwise when viewed from the top
Power transmission Via automatic centrifugal clutch
Dimensions (L x W x H) 1,790 x 393 x 296 mm 1,790 x 750 x 525 mm
Dry weight 5.0 kg 5.2 kg
Accessories
Nylon cutter *3blade、*Cuter Case
*Shoulder belt、*Protection goggles
Tool set
*: Other than U.S.A.
SPECIFICATIONS

-3-
(Superior specifications: )
Maker HITACHI
Model CG 25EUS (L) A B
Engine type – Forced air-cooling
four-cycle OHV
Forced air-cooling
four-cycle OHC
Forced air-cooling
four-cycle OHV
Engine
displacement mL 25 25 24.5
Max. power output kW 0.81 (1.1 hp) 0.81 (1.1 hp) 0.7 (0.9 hp)
Secondary exhaust
regulation mL
Other than U. S. A. : 550
U. S. A. : 500 550 500
Engine oil tank
capacity mL 80 80 80
Gas emission (THC +
NOx)
g/kWh 32 25 32
Fuel consumption g/kWh 450 460 440
Oil consumption mL/h 3.0 2.6 –
(Front
handle) 4.8 5.8 5.2
Vibration
level (Rear
handle)
m/s2
3.2 8.3 5.6
Noise level dB (A) 87 91 87
Engine volume L 4.7 4.9 4.8
Outer dimensions
(L x W x H) mm 1,790 x 393 x 296 1,770 x 368 x 305 1,760 x 330 x 265
Mass (catalog data /
measured data) kg 5.0/5.0 5.2/5.46 5.2/–
COMPARISONS WITH SIMILAR PRODUCTS

-4-
1.Safety Instructions
In the interest of promoting the safest and most efficient use of the Model CG 25EUS Engine Grass
Trimmer by all of our customers, it is very important when concluding a sale that the salesperson carefully
ensure that the customer seriously recognizes the importance of the Handling Instructions and precautions
indicated on the Caution Plate and Name Plate attached on the product.
For how to handle, maintain, inspect, and store the Model CG 25EUS Engine Grass Trimmer, refer to the
Handling Instructions, and instruct the customer on proper use, particularly how to conduct periodic
inspection. Also pay attention to the supply system for consumables and the system for product repair.
A. Handling Instructions
Although every possible effort has been made in the design, manufacturing, and testing phases to ensure
the safety of the Model CG 25EUS Engine Grass Trimmer, this product inevitably involves an inherent risk
in use. To avoid unnecessary risk and ensure that the customer uses the product safely and efficiently, the
Handling Instructions describe safety precautions specific to the Model CG 25EUS Engine Grass Trimmer.
Therefore, when concluding a sale, make sure that the customer carefully reads the safety precautions,
and give the customer appropriate guidance.
B. Caution Plate
The Name Plate and Caution Plate attached on the Model CG 25EUS Engine Grass Trimmer describe
precautions on the safe use of the product.
[For Western and Northern Europe]
[For North America]
[For Western Europe and Northern Europe]
[For North America]
PRECAUTIONS ON SALES PROMOTION

-5-
2. Specific Instructions for Customers
(1) Proper startup and stopping procedures
Thoroughly instruct the customer on how to start and stop this tool. With regard to startup, make sure
that the customer fully understands the difference in startup procedure between two situations when the
engine is cold and when it has been warmed up.
(2) Proper fuel mixture
This tool is equipped with a four-cycle gasoline engine. Instruct the customer to only use unleaded
regular gasoline for this tool. Using an alcohol-blended fuel for this tool may damage the engine and
fuel line.
Also instruct the customer not to use a mixture of gasoline and engine oil as fuel. Using such a mixture
as fuel may cause startup failure, reduce power output, and clog the fuel line.
(3) Proper engine oil
This tool requires engine oil in addition to fuel.
•Instruct the customer to use SAE 10W-30 oil, which is intended for four-cycle engines.
•Because this tool is shipped without engine oil, instruct the customer to supply engine oil to this tool
before use.
•Instruct the customer to always check the engine oil level before using this tool, and replenish the
engine oil tank whenever the engine oil level is low.
•Instruct the customer to replace engine oil after about 10 hours of initial operation when using this tool
for the first time, and then replace engine oil after every 50 hours of subsequent operation.
•Note that more engine oil than normal is consumed during the initial 10 hours of operation.
(4) Proper storage
Instruct the customer to remove fuel from the fuel tank and continue idling operation until the engine
stops in order to remove fuel from inside the carburetor when not using this tool for a long time. Using
old fuel may cause tool failure.
Instruct the customer to store this tool with its main pipe positioned horizontally or lean it against a
structure with its cutter facing up for storage. Storing this tool with its cutter facing down may cause
engine oil to leak. Also instruct the customer to use sufficient care when leaning this tool against a
structure, in order to prevent it from falling down.
(5) Exclusive use of genuine cutter blades
Fully inform the customer of the applicable standard (M10 left-handed thread at pitch of 1.25) for nylon
head attachment, outer cutter blade diameter (max. Ф230 mm),and the type of cutter blade. Using an
incompatible cutter blade may not only shorten the tool’s service life but also result in an accident.

-6-
Situation Cause Measure
The piston ring is stuck.
The connecting rod bearing is
stuck
Disassemble the engine and
replace the faulty part
A valve is damaged Replace the faulty part
Starter handle
cannot be
pulled
The crankshaft does
not rotate
The crank gear or cam gear is
damaged Replace the faulty part
The fuel tank is empty Replenish the fuel tank with
fuel
The fuel filter is clogged Clean or replace the part
The air hole in tank cap is faulty Replace the faulty part
The carburetor is clogged with
foreign matter Clean the part
The plug does not
become wet with fuel
after repeated startup
operation
Throttle operation is
inappropriate
Perform appropriate startup
operation
The spark plug is stained or
faulty Clean or replace the part
The spark plug cap is not
properly connected Inspect and replace the part
The high-voltage cord or other
cable broke, or its connection is
faulty
Repair or replace the part
The high-voltage cord or other
cable is grounded Repair the part
No spark
The ignition coil broke or is
faulty Replace the faulty part
Short-circuited due to foreign matter between the plug
electrodes
Remove the foreign matter.
If this problem recurs often,
disassemble the engine and
clean the parts
The piston ring is faulty
The piston is worn
A cam is damaged
The crank gear or cam gear is
damaged
Replace the faulty part
Startup is
impossible
No compression
Carbon accumulated on a
valve Clean the part
The spark plug is stained or
faulty Clean or replace the part
Weak spark The air gap between the
magneto rotor and ignition coil
is faulty
Perform adjustment
The piston ring is worn Replace the faulty part
Low compression Carbon accumulated on a
sealed valve surface Clean the part
The idling speed is too low Perform adjustment
Idling stops
although
startup is
possible
Good spark and
compression The carburetor is clogged with
foreign matter
Disassemble the engine and
clean the part
TROUBLESHOOTING GUIDE

-7-
Situation Cause Measure
The fuel filter is clogged Clean or replace the part
Loose nuts Repair the parts
The engine stalls
Worn push rod
Worn valve
Worn pivot
Worn rocker arm
Valve
clearance is
extended
Worn tappet
Replace the faulty part
The muffler is clogged with
carbon
The air cleaner is clogged
Starts, but when
it accelerates…
Poor acceleration;
no increase in rpm
Carbon accumulated on a
valve
Clean the part
Fluctuating rpm at
high speed
The carburetor is clogged with
foreign matter Clean the part
Starts, but … Excessive fuel
consumption The air cleaner is clogged Clean the part
The piston ring is worn
The cylinder is worn
The piston is deformed
Chain oil is not discharged
The oil seal is worn or
damaged
Replace the faulty part

-8-
This section describes repair, focusing on sections that may require frequent repair. Refer to the previous
section (TROUBLESHOOTING GUIDE) as the context for the following descriptions.
1. Precautions on Maintenance, Inspection and Repair
• Never place fuel near a source of fire because the fuel is inflammable.
• When reassembling this tool after disassembly, use new gaskets.
• Before overhauling this tool, transfer fuel and engine oil from this tool to separate containers. Before
disassembling this tool, wait until the engine is sufficiently cooled down.
• When repairing, starting or operating this tool, be careful not to touch any hot parts (such as the muffler,
high-voltage cable or spark plug) that could cause a burn injury or electric shock.
• Before operating this tool with its cutter blade, make sure that no other person is around you.
• When repairing this tool in a room or other location with poor ventilation, be sure to ventilate the place.
• After repair, check whether the throttle lever returns to the idling position and the engine stops when you
set the stop switch to the stopping position.
2. Inspection Criteria for Each Section and Consumable Parts
Item CG 25EUS
Idling speed min-1 2,500 to 3,500
Max. no-load revolution (with cutter
blade mounted) min-1 9,500 to 11,500
Clutch engaging min-1 3,900 to 4,900
Acceleration – Acceleration must be smooth.
Valve clearance (in cold state) mm Exhaust: 0.1 Intake: 0.1
Gap between magneto rotor and ignition
coil mm 0.3 to 0.4
Spark plug – NGK CMR-5H
Gap between spark plug electrodes mm 0.6 to 0.7
REPAIR GUIDE

-9-
Piston ring is damaged Replacement
Piston or cylinder is stuck Replacement
Needle bearing on connecting rod is damaged Replacement
Ball bearing is stuck Replacement
Magneto rotor touches the ignition coil Inspection and
adjustment
Recoil starter is damaged Inspection and
replacement
Valve is damaged Replacement
Oil pump (inner or outer rotor) is
damaged Replacement
Crank gear or cam gear is damaged Replacement
Stop switch is not set to starting position Setting the switch to
starting position
Spark plug is stained or faulty Cleaning and
inspection
High-voltage cord or other cable broke,
or its connection is faulty Inspection
High-voltage cord or other cable is
grounded Inspection
Ignition coil broke or is faulty Replacement
Clearance between magneto rotor and
ignition coil is too large Adjustment
Fuel filter (pump filter body assembly)
was clogged
Cleaning or
replacement
Fuel pipe is cracked or creased Replacement
Air hole on tank cap is faulty Replacement
Pump diaphragm of carburetor is faulty Replacement
Carburetor is clogged with foreign matter Cleaning
Piston ring is faulty Replacement
Piston ring is worn Replacement
Piston is worn Replacement
Cylinder is worn Replacement
Cam is damaged Replacement
Crank gear or cam gear is damaged Replacement
Valve is damaged Replacement
Carbon accumulated on a sealed valve
surface Cleaning
Fuel filter (pump filter body assembly) is
clogged
Cleaning or
replacement
Warm-up is insufficient especially in a
cold environment Warm-up operation
Valve clearance is extended Inspection and
adjustment
Repair Flowchart
OK
NG
OK
NG
The engine stalls
Pull the starter handle.
Check whether there is
compression and the handle c
a
be pulled
The engine starts.
Pull the throttle lever, and
check what happens
NG
OK
Check whether there is
compression
OK
OK
NG
Remove the spark plug.
Check whether the plug sparks
Mount the sparek plug and spark
plug cap, and perform correct
startup operation.
Check whether the spark plug
head is wet with fuel

-10-
Cylinder exhaust port or muffler is
clogged with carbon Cleaning
Cleaner element is clogged Cleaning
Valve clearance is extended Inspection and
adjustment
Carbon accumulated on a sealed valve
surface Cleaning
High-speed fuel line of carburetor is
clogged with foreign matter Cleaning
Pump diaphragm of carburetor is faulty Replacement
Air is suctioned through a gaske Inspection and
replacement
Valve clearance is extended Inspection and
replacement
Idling speed is too low Adjustment
Idling speed is too low Adjustment
Idling speed is too high Adjustment
Clutch is worn or faulty Inspection and
replacement
The speed fluctuates
The engine stalls
The engine stalls
OK
OK
The speed does
not increase
OK
Check whether the speed
increases normally
Check whether the engine
can suddenly decelerate
from high speed
Check whether the cutter
blade begins rotating in the
idling state
Start the engine. Check
whether the engine can be
set to the idling state
Check that the engine speed
increases by pulling the throttle
lever
OK
The cutter blade
begins rotating

-11-
Ignited Sparks
Metallic portion of the engine
High-voltage cord
Spark Plug
(NGK CMR5H) [22]
Spark PlugCap [20]
●Checking for sparks
[Bold] numbers in the descriptions below correspond to item numbers in the Parts List and exploded view
assembly diagram for the Model CS 25EUS.
Be sure to stop the engine before disassembly.
1. How to check for sparks by the spark plug
CAUTION:
• When pulling the Starter Knob [86],be careful not to
touch the metal part of the Spark Plug (NGK CMR5H)
[22] in order to avoid electric shock.
•Wipe off any fuel around the Spark Plug (NGK CMR5H)
[22],and make sure there is no risk of fire
(1) Remove the Spark Plug (NGK CMR5H) [22] from Cylinder
(A) [47].
If carbon accumulated on the electrodes of the Spark Plug
(NGK CMR5H) [22], use a wire brush to clean the
electrodes. If the gap between electrodes is improper,
adjust it. Use a cloth to wipe off any fuel on the electrodes.
(2) Fit the Spark Plug (NGK CMR5H) [22] into the Spark Plug
Cap [20], and bring the electrodes into contact with a
metal part of the engine. In this status, set the Stop Switch
[154] to the starting position, and then pull the Starter
Knob [86].
(3) When normal, the electrodes of the Spark Plug (NGK
CMR5H) [22] generate a flick and spark.
2. Adjusting the gap formed between the Magnet Rotor Ass’y and Ignition Coil
(1) Remove Hex. Socket HD. Bolt (W/SP. Washer)
M5 x 20 [122] and Tapping Screw D4.5 x 16
[128], and then remove the Fan Case [146].
(2) Loosen Hex. Hole Bolt M4 x 18/WS [139]
so as to temporarily secure the Ignition Coil
Set [140].
(3) Adjust the circumferential magnet of the
Magnet Rotor [138] and Ignition Coil Set
[140] to set a gap of 0.3 to 0.4 mm.
(4) In this status, fully tighten the Hex. Hole
Bolt M4 x 18/WS [139].
Repair Procedures
●Spark plug
Gap between
electrodes
(
0.6 to 0.7 mm
)
Remove carbon
●Magnet Rotor Ass’y and Ignition Coil
Magnet Rotor [138]
0.3 to 0.4 mm
Ignition Coil Set [140]
Hex. Hole Bolt M4 x 18/WS
[
139
]

-12-
3. Electric Wiring
The figure on the right shows the electric wiring.
(1) Connect the Stop Cord [141] to the Ignition Coil
Set [140], and then connect the Earth Cord
[143] to the Ignition Coil Set [140] with the Hex.
Hole Bolt M4 x 18/WS [139].
(2) Connect the two Stop Switch Cords [155] to the
connectors of the Stop Switch [154], and then
connect the two cords separately to the Stop
Cord [141] and Earth Cord [143].
4. Adjusting the Carburetor
(1) Use the following screw for carburetor adjustment:
• Idle Adjust Screw
This screw adjusts the airflow rate at idling.
Turning this screw clockwise increases engine
speed; turning it counterclockwise decreases
engine speed.
(2) Standard setting of carburetor
• Idle Adjust Screw
2,500 to 3,500 min-1 (revolutions per minute)
(Confirm that the cutter blade does not rotate.)
(3) Fine adjustment
• Idling adjustment
Turn the Idle Adjust Screw to adjust to the rpm
speed at which the engine runs stably without
rotating the cutter blade.
●Electric Wiring
Stop Switch [154]
Stop Switch Cord [155]
Hex. Hole Bolt
M4 x 18/WS [139]
Earth Cord [143]
Stop Cord [141]
Spark Plug (NGK CMR5H) [22]
S
p
ark Plu
g
Ca
p
[
20
]
I
g
nition Coil Set [140]
●Idle Adjust Screw
Idle Adjust Screw

-13-
5. Adjusting the Valve Clearance
CAUTION:
•Be sure to adjust the valve clearance with the engine sufficiently cooled down.
(1) Remove the two Tapping Screw D4.5 x 16 [128] and upper Seal Lock Screw M4 [88] fixing the Recoil
Starter Body Assy [80], and then remove the Engine Cover [129].
(2) Remove Hex. Socket HD. Bolt (W/SP. Washer) M5 x 20 [168], and then remove the Fan Case [146].
(3) Remove Machine Screw (W/SP. Washer) M4 x10 [1], and then remove the Cylinder Head Cover [2].
If the Cylinder Head Cover [2] cannot be easily removed due to liquid packing applied between the
Cylinder Head Cover [2] and Cylinder (A) [47], use a plastic hammer to lightly hit the side of Cylinder
Head Cover [2]. Be careful not to deform the Cylinder Head Cover [2] by hitting it.
(4) Remove the Spark Plug (NGK CMR5H) [22].
(5) Slowly rotate the Magnet Rotor [138] counterclockwise. After the Exhaust Valve [50] and Intake Valve
[49] operate sequentially in this order, while looking through the Spark Plug (NGK CMR5H) [22]
mounting hole on the Cylinder (A) [47], rotate the Magnet Rotor [138] by a half turn until the Piston [60]
is positioned at the top dead center.
(6) Insert a feeler gauge between the Rocker Arm [8] and Exhaust Valve [50], and between the Rocker Arm
[8] and Intake Valve [49] to check the valve clearance. Adjust the valve clearance if outside the range
from 0.1 to 0.2 mm.
(7) Use a wrench to fix the lower of the two Lock Nut M5 [3] onto the Shaft Bolt [9]. In this status, loosen the
upper Lock Nut M5 [3], and then loosen the lower Lock Nut M5 [3].
CAUTION:
• Loosening the upper Lock Nut M5 [3] without the lower Lock Nut M5 [3] being fixed will loosen
the Shaft Bolt [9]. Therefore, be sure to fix the lower Lock Nut M5 [3] before loosening the
upper Lock Nut M5 [3].
(8) Insert a 0.35-mm feeler gauge between the Rocker Arm [8] and Exhaust Valve [50] or Intake Valve [49].
In this status, tighten the lower Lock Nut M5 [3] until it lightly touches the Pivot Rocker Arm [4]. Then,
while fixing the lower Lock Nut M5 [3] so that it does not turn, tighten the upper Lock Nut M5 [3] with
torque of 3.5 ± 0.5 N·m.
(9) Pull the Starter Knob [86] several times, position the Piston [60] at the top dead center as described in
step (5) above, and then use a feeler gauge to check whether the valve clearance is 0.1 to 0.2 mm.
(A tip on adjustment)
If the lower Lock Nut M5 [3] turns while the upper Lock Nut M5 [3] is being tightened, the adjusted valve
clearance may exceed the range from 0.1 to 0.2 mm. Therefore, be sure to use a wrench to fix the lower
Lock Nut M5 [3] before tightening the upper Lock Nut M5 [3].
●Adjusting the Valve Clearance
Exhaust valve side
Intake valve side

-14-
1. Fan Case Ass’y (A)
Disassembly:
Remove Hex. Socket HD. Bolt (W/SP. Washer) M5 x 20 [168] and Tapping Screw D4.5 x 16 [128], and
then remove the Fan Case [146]. Next, remove the Pipe Holder A [124], Anti Vibe Rubber (A) [123],
Pipe Holder B [125], and Anti Vibe Rubber (B) [126] in this order.
When it is necessary to remove the Clutch Shaft Comp [147], remove the Retaining Ring for D12 Shaft
[144], and then place the Fan Case [146] so that its surface to be mated with the crankcase faces down,
while being careful about positioning of the Ф4.1 pins and spigot. Then use a hand press to slowly push
the shaft of Clutch Shaft Comp [147] in order to remove the Clutch Shaft Comp [147], while being
careful not to damage the ball bearing in the Fan Case [146].
Reassembly:
While holding the inner ring of the ball bearing in the Fan Case [146], slowly press-fit the Clutch Shaft
Comp. [147], and then mount the Retaining Ring for D12 Shaft [144].
Mount Anti Vibe Rubber (B) [126], Pipe Holder B [125], Anti Vibe Rubber (A) [123], and Pipe Holder A
[124] on the Fan Case [146] in this order.
If it is difficult to fit in Pipe Holder A [124], apply a thin coating of gasoline to its surfaces that contact Anti
Vibe Rubber (A) [123].
Disassembl
y
and Reassembl
y
●Fan Case Ass’y (A)
Hex. Socket HD. Bolt
(W/SP. Washer) M5 x 20 [168]
A
nti Vibe Rubber (A) [123]
Pipe Holder B [125]
Fan Case [146]
Pipe Holder A [124]
A
nti Vibe Rubber (B) [126]
Shaft portion
Retaining Ring
for D12 Shaft [144]
Clutch Shaft Comp [147]

-15-
●Muffler Ass’y
2. Muffler Ass’y
Disassembly:
Loosen Hex. Socket HD. Bolt M5 [11], and then remove the Muffler [12], Muffler Gasket (A) [13], Wind
Guide Plate (B) [14], and Muffler Cover (A) [15].
Reassembly:
Wipe off any carbon from the exhaust inlet and outlet of the Muffler [12],and then mount the removed
parts in the order shown in the figure below. Tighten the Hex. Socket HD. Bolt M5 [11] one after another
in steps to prevent the Muffler [12] from being tilted.
Hex. Socket HD. Bolt M5 [11]
Muffler [12]
Muffler Gasket (A) [13]
Wind Guide Plate (B) [14]
Muffler Cover (A) [15]
Washer 5 [105]

-16-
3. Cleaner, Carburetor and Insulator
Disassembly:
Loosen the Cover Fixing Bolt [104], and then remove the Cleaner Cover [103] and Cleaner Element
[102]. Loosen Machine Screw (W/SP. Washer) M5 [99], and then remove the Cleaner Body [94],
Carburetor [32], and other parts. Loosen Machine Screw (W/Washers) M5 x 30 [26], and then remove
the Insulator [25] and other parts.
Reassembly:
When mounting the Insulator [25], remember to attach the Lock Nut M5 [107].
Mount the removed parts in the order shown in the figure below. Before mounting the Cleaner Element
[102] in the Cleaner Cover [103], wash the Cleaner Element [102] with gasoline, and then dry it well.
Cover Fixing Bolt [104]
Machine Screw
(W/SP. Washer) M5 [99]
Cleaner Cover [103]
Cleaner Element [102]
Cleaner Body [94]
Wind Guide Plate (A) [24]
Insulator Gasket [23]
Insulator [25]
Machine Screw
(W/Washers) M5 x 30 [26]
Carbureto
r
Gasket [27]
Carburetor [32]
Insulator Gasket (B) [31]
Throttle Wire Fixing Plate [30]
Lock Nut M5 [107]
●Cleaner, Carburetor and Insulator

-17-
●Spark Plug Cap
4. Ignition Coil and Spark Plug Cap
Disassembly:
Loosen Hex. Hole Bolt M4 x 18/WS [139], and then remove the Ignition Coil Set [140].
To remove the Spark Plug Cap [20], add a drop of oil into the Spark Plug (NGK CMR5H) [22] hole in the
Spark Plug Cap [20], move the high-voltage cord back and forth to spread the oil, and then slowly pull
out the Metal Fitting of Plug Cap [21] so that it is not extended.
Reassembly:
Insert the high-voltage cord of Ignition Coil Set
[140] into the Spark Plug Cap [20], and pull
out the high-voltage cord from the Spark Plug
(NGK CMR5H) [22] hole. Fit the Metal Fitting
of Plug Cap [21] onto the pulled-out high-
voltage cord, and then draw back the high-
voltage cord into the Spark Plug Cap [20]
while being careful to prevent the Metal Fitting
of Plug Cap [21] from coming off.
When mounting the Ignition Coil Set [140], be
careful to maintain the correct gap between
the Ignition Coil Set [140] and magneto rotor
assembly.
(See Section 2 in "Repair Procedures.")
Finally check that the Stop Cord [141] and
Earth Cord [143] are not damaged.
5. Tank and Recoil Starter Ass’y
Disassembly:
Before disassembling the Tank [158], make
sure that it contains no gasoline.
Loosen Hex. Hole Bolt M5 x 25/S [162], and
then remove the Stand [160] and Tank [158].
To remove the Recoil Starter Body Ass’y [80],
loosen Seal Lock Screw M4 [88], and then
remove the Recoil Starter Body Ass’y [80].
Reassembly:
Before reassembly, check the Fuel Pipe [163]
and Fuel Pipe (Pink) [164] for any damage. If
any deterioration, crack or gasoline leak is
found, replace both parts.
Use a piece of wire to draw out the Pump Filter
Body [159] from the fuel inlet of the Tank [158].
If the Pump Filter Body [159] is dirty, clean it
with a cloth dipped in gasoline.
To check for clogging of the Pump Filter Body
[159], remove the Pump Filter Body [159] from
the Fuel Pipe [163], and check whether air can
be blown through the Pump Filter Body [159].
If the Pump Filter Body [159] is clogged,
replace it.
●Tank
Hex. Hole Bolt M5 x 25/S [162]
Stand [160]
Tank [158]
Fuel Pipe (Pink) [164]
Fuel Pipe [163]
Pump Filte
r
Body [159]
High-Voltage Cord
Spark Plug Cap [20]
Metal Fitting of Plug Cap [21]