O.S. Engines 21XZ-B User Manual

Expressly for 1/8 off-road buggy racing competitions

MAX-21XZ-B Ver.

It is of vital importance, before attempting to operate your
engine, to read the general 'SAFETY INSTRUCTIONS
AND WARNINGS' in the following section and to strictly
adhere to the advice contained therein.

Also, please study the entire contents of this
instruction manual, so as to familiarize yourself with
the controls and other features of the engine.

SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE

Remember that your engine is not a " toy ", but a
highly efficient internal-combustion machine whose
power is capable of harming you, or others, if it is
misused or abused. As owner, you, alone, are
responsible for the safe operation of your engine, so
act with discretion and care at all times. If at some
future date, your O.S. engine is acquired by another
person, we would respectfully request that these
instructions are also passed on to its new owner.

The advice which follows is grouped under two
headings according to the degree of damage or
danger which might arise through misuse or neglect.

WARNINGS

These cover events which might involve serious
(in extreme circumstances, even fatal) injury.

NOTES

These cover the many other possibilities, generally less
obvious sources of danger, but which, under certain
circumstances, may also cause damage or injury.

With this engine, the piston will feel tight at the
top of its stroke (TDC) when the engine is cold.
This is normal. The cylinder bore has a slight
taper. The piston and cylinder are designed to
achieve a perfect running clearance when they
reach operating temperature.

When the engine is cold.

NOTES WHEN APPLYING AN ELECTRIC STARTER

ENGINE CONSTRUCTION

Near TDC

Cylinder
Liner

Crankshaft

Slight taper

Do not over-prime. This could cause a
hydraulic lock and damage the engine on
application of the electric starter.
If over-primed, remove glowplug, close
needle-valve and apply starter to pump out
surplus fuel. Cover the head with a rag to
prevent any pumped out fuel from getting into
your eyes.

Piston

When the engine is hot.

WARNINGS

Model engine fuel is poisonous. Do not
allow it to come into contact with the eyes
or mouth. Always store it in a clearly marked
container and out of the reach of children.

Model engine fuel is also highly flammable.
Keep it away from open flame, excessive
heat, sources of sparks, or anything else
which might ignite it. Do not smoke or allow
anyone else to smoke, near to it.

Model engines generate considerable
heat. Do not touch any part of your engine
until it has cooled. Contact with the
muffler (silencer), cylinder head or
exhaust header pipe, in particular, may
result in a serious burn.

Never operate your engine in an enclosed space.
Model engines, like automobile engines, exhaust
deadly carbon-monoxide. Run your engine only in
an open area.

NOTES

This engine is intended for model cars. Do not
attempt to use it for any other purpose.

Mount the engine in your model securely, following
the manufacturers' recommendations, using
appropriate screws and locknuts.

NOTES ON OPERATION

This engine is constructed from the very best
materials available and to the very highest
engineering standards, using the most
advanced precision machinery. However, the
extremely high stresses imposed by car racing
operation under very severe conditions, as
well as stresses which are exacerbated by the
use of powerful fuels containing very high
concentrations of nitromethane, constitute
hazards which are beyond a manufacturer's
control. Accordingly, we regret that it is not
possible to extend our usual warranty terms to
this particular engine -i.e. no guarantee is
offered against material wear, or damage
resulting therefrom, in actual use.

Please do not run on a public street, this could
cause serious accidents, personal injuries
and/or propetry damage.

Please do not run near pedestrians or small
children.

Please do not run in small or confined areas.

Please do not run where loud noises can disturb
others, such as hospitals and residential areas.

NOTE
As delivered, the engine has the carburetor
lightly fit into its intake. Secure it changing its
angle according to the car chassis.

ABOUT THE ENGINE

The MAX-21XZ-B Ver.II is expressly designed for 1/8
off-road racing buggy featuring smooth acceleration
and easy handling.
Newly designed single-adjust carburetor ensures
easier adjusting.

Glow Plug P3 T-type head (Turbo head)
1piece

Exhaust Seal Ring 1piece

O.S. SPEED Dust Cap Set For 12-30 Class
3mm, 16mm, 18mm 1piece each

GUARANTEE

While Operating

Standard accessories

(Hot Type)

Install an effective silencer (muffler). Frequent close
exposure to a noisy exhaust (especially in the case
of the more powerful highspeed engines) may
eventually impair your hearing and such noise is
also likely to cause annoyance to others over a wide
area.

The wearing of safety glasses is also strongly
recommended.

Take care that the glowplug clip or battery leads do
not come into contact with rotating parts. Also check
that the linkage to the throttle arm is secure.

For their safety, keep all onlookers (especially small
children) well back (at least 20 feet or 6 meters)
when preparing your model for running.

Before starting the engine, always check the
tightness of all the screws and nuts especially those
of joint and movable parts such as throttle arm.
Missing retightening the loose screws and nuts
often causes the parts breakage that is capable of
harming you.

To stop the engine, fully retard the throttle stick and
trim lever on the trans-mitter, or, in an emergency,
cut off the fuel supply by pinching the fuel delivery
line from the tank.

Warning! Immediately after a glowplug-ignition engine
has been run and is still warm, conditions sometimes
exist whereby it is just possible for the engine to abruptly
restart if it is rotated over compression WITHOUT the
glowplug battery being reconnected.

TOOLS, ACCESSORIES, etc.

The following items are necessary for operating the engine.

Items necessary for starting

FUEL

Generally, it is suggested that the user selects a fuel that is
commercially available for model two-stroke engines When
the brand of fuel is changed, or the nitro content increased, it
is advisable to repeat the running-in procedure referred to in
the RUNNING-IN paragraphs. Please note
that with high-nitro fuels, although power
may be increased for competition purposes,
glowplug elements do not last as long and
engine life will be shortened.

FUEL FILTER

To installed in the fuel line between fuel
tank and carburetor to prevent foreign
matter from entering the carburetor.

GLOWPLUG IGNITER

Commercialy available handy glowplug
heater in which the glowplug battery and
battery leads are integrated.

STARTER BOX

For starting the engine.

FUEL PUMP

For filling the fuel tank, a simple, polyethylene
"squeeze" bottle, with a suitable spout, is
required.

O.S. SPEED SILICONE FUEL LINE

The connection between the fuel tank and the engine.

2.5mm ID

TOOLS

O.S. SPEED DRIVER TOOLS

O.S. SPEED FLYWHEEL KEY

O.S. SPEED
CLUTCH WRENCH & ADJUSTER

O.S. SPEED FLYWHEEL PULLER

O.S. SPEED PLUG WRENCH

(optional extra)

BASIC ENGINE PARTS

Outer Head

Carburetor
Type 22B2

Crankshaft

Crankshaft Bearing (Front)

CARBURETOR CONTROLS STANDARD POSITIONS
(POSITIONS WHEN THE ENGINE LEAVES THE FACTORY)

Three adjustable controls are provided on this
carburetor.

Needle Valve

Dust Cover

Throttle Stop
Screw

Thermo Insulator

The Needle-Valve:

For adjusting air/fuel ratio (air-fuel mixture) at maximum
rpm (fully opened throttle).

Close
(Clockwise)

Open
(Counter-clockwise)

[Standard Position]

3 and 1/4 turns opened from the fully closed position.

[Fully closed position]

Turn the needle-valve clockwise until it stops.
This is the fully closed position.
Do not force it to turn further.

The Metering Needle:

For adjusting idle and acceleration feeling.

Carburetor Body

The Throttle Stop Screw:

For setting the minimum idle speed:

Note:
Sketch shows the carburetor reducer removed.

NOTE:
The Metering Needle Valve is set at the standard
position when the engine leaves the factory,
readjustment may be necessary, occasionally to allow
for changes in fuel formula and climatic conditions
Readjust the controls only when satisfactory results
cannot be obtained with the standard positions
following the instructions mentioned in the
“CARBURETOR ADJUSTMENT” section.

Needle Valve

Ball Link

[Standard Position]

Flush with the ball link body.

Metering Needle

Slide Valve

[Standard Position]

Approx 0.5mm

Carburetor Body

Slide Valve

Exhaust

Cover Plate

Mounting Lugs

Crankcase

Carburetor Reducer

Ball Link

Metering Needle

INSTALLATION OF THE CARBURETOR

As delivered, the engine has its carburetor lightly installed
in the intake boss. Secure it as follows.

Rotate the retainer nut
gently until it stops.

Tighten a further
120-180

"O" Ring

Loosen the retainer screw, rotate the carburetor to its

1.
correct position and make sure that it is pressed well
down into the intake boss, compressing the rubber
gasket, before retightening screw.

Rotate the retainer screw gently until it stops, then

2.

tighten a further 120-180 .
Do not overtighten the screw as this will damage the
thermo insulator.

Note
Be careful not to damage the O rings when
removing the carburetor retainer from the engine.
First, remove the retainer Retaining screw, then
pull out each part. Do not push the part in or
damage the O rings.

ENGINE INSTALLATION

Make sure that the vehicle's engine mounting surfaces
are level and in the same plane. Poor installation may
cause distortion of the crankcase, bearings, etc.,
resulting in erratic running and loss of performance.
The recommended screws for securing the engine are
3mm or 4-40 steel Allen hexagon socket type. If existing
holes in the engine mount do not align perfectly with
engine mounting lugs, enlarge them slightly with a
needle-file so that screws are in alignment with the
mounting holes.

Chamfer inside edges of bearers.

The engine bottom may interfere with chassis of
some models. In this case, file off the chassis
so that the engine may not interfere with the
chassis when it is installed.

Note:
Be sure to use a collet supplied when use a
optional 28XZ Hyper Flywheel Set.

STARTING THE ENGINE & RUNNING-IN ('Breaking-in)

Running- in is a procedure for an engine to come
close to actual running conditions (fuel, r.p.m.,
engine temperature, etc.).

Excessively rich running and prolonged low speed
running should be avoided. Prolonged low speed
running and low temperature running may result
in the oil in the fuel becoming gelled and the
piston/liner becoming stuck together.

"O" Ring

Retaining Screw

Do not allow bottom
of crankcase to
touch chassis.

NOTE

PRESSURIZED FUEL SYSTEM

It is recommended that a muffler pressurized fuel
feed system be used so that the fuel may be stably
fed to the carburetor.

The following procedure is suitable when a fuel
containing 30% nitro-methane is used.

Set the carburetor controls at the standard positions

1.
(positions when the engine leaves the factory.)

Switch the transmitter and make sure that each

2.
linkage moves correctly.

Make sure rotating direction of the starter box is

3.
correct (counter-clockwise seen from the front edge
of the crankshaft), and turn the engine with the
starter box to draw fuel into the engine.

Connect glowplug battery lead to heat the plug and

4.
start the engine with the starter box.
When the engine does not start or stops right after
being started, try the followings.

Close the needle-valve approx. 90° from the
standard position.

Set the throttle opening a
little wider (approx. 1mm)
than the standard setting
by adjusting the Throttle
Stop Screw.

5.

When the engine starts, warm it up by repeatedly
increasing the rpm to medium speed and back
again to a fast idle with the mixture set very rich,
glowplug connected, and the driving wheels clear of
the ground. The rich mixture will provide adequate
lubrication and cooling, indicated by profuse
exhaust smoke.

Attention:

It is vitally important to set the
throttle at the correct position
before starting the engine. If
the engine is allowed to run
with the throttle too far open
under ''no load'' conditions
(i.e. with the driving wheels not in contact with the
ground) it will rapidly over-heat and may be
seriously damaged.

6.

When the engine is warmed up, disconnect the
glowplug battery and try running the car on the
track. If the engine stops soon after running at
around mid speed, the mixture is too rich. Close the
needle-valve 15~30°.
If the engine still stalls, close the metering needle
15~30°. Run the car on the track until one tank of
fuel has been consumed, then close the needle-valve
very little (within 10°).

7.

Repeat this procedure (close needle-valve very little
after one tank of fuel has been consumed) until approx.
2 liters of fuel have been consumed, extending
gradually the full throttle running time at the straight.
Carefully observe the exhaust smoke.
Be sure to run the engine with visible white smoke at all
times. If the smoke is not visible, the needle-valve is
closed too far.

Now the RUNNING-IN (Breaking-in) is completed.

Note:
In the event of any major working parts (e.g.
piston/cylinder liner assembly) being replaced or
the fuel being changed, especially to high nitro
fuel, the complete running-in should be repeated.

How to stop the engine

To stop the engine, close the
throttle to idle speed and shut it off
completely with the trim lever on the
transmitter then cut off the fuel
supply by pinching the fuel delivery
tube to the carburetor.

Warning!
Do not touch rotating parts, engine and silencer
when stopping the engine as they become very hot,
and contact with them may result in a serious burn.

approx 1mm

Fuel

CARBURETOR ADJUSTMENT

Carburetor adjustment should be carried out only after
the running-in has been completed.

Needle Valve

Open

More fuel

1.

NEEDLE VALVE ADJUSTMENT

Close

Less fuel

Metering Needle

Open

Close

More fuel Less fuel

Run the vehicle (with throttle fully open) over the
longest available straight course a few times to
observe the model’s speed. Return the vehicle to the
starting point and close the Needle-valve 15°and
repeat the run, taking note of the improvement in
performance.
Continue with further runs, gradually reduce the
Needle-valve setting aiming to achieve the highest
straight-line speed (optimum position).
Remember, however, if the Needle-valve is closed too
far, the engine will overheat, accompanied by visibly
diminished exhaust smoke and the model will lose
speed. At this point, throttle down immediately, stop
the vehicle and reopen the Needle-valve 30~45°.

METERING NEEDLE ADJUSTMENT

2.

After setting the Needle-valve at optimum position,
run the vehicle a few times at the straight line.
With the engine running, close the throttle and
allow it idle for about five seconds, then reopen the
throttle fully.
If, at this point, the engine puffs out an excessive
amount of smoke and the vehicle does not
accelerate smoothly and rapidly or even stops, it is
probable that the idle mixture is too rich. In this
case, turn the Metering needle clockwise 15~30°.
If, on the other hand, the engine tends to speed up
momentarily and then cut out abruptly when the
throttle is opened, the idle mixture is too lean. In
this case, turn the Metering needle counter-clockwise
15~30°.

3.

THROTTLE STOP SCREW ADJUSTMENT

If the engine runs too fast with the throttle closed, the
throttle stop screw should be turned counter-clockwise
to allow the throttle opening to be reduced.

OPTIMUM MIXTURE CONTROL POSITION

With the optimum mixture control position, light smoke
is visible during high speed running and the engine rpm
increase smoothly during acceleration. Carry out
adjustment 1.~3. patiently until the engine responds
quickly and positively to the throttle control.
Remember that, if the engine is operated with the fuel/air
mixture slightly too lean, it will overheat and run
unevenly. As with all engines, it is advisable to set both
the needle-valve and metering needle slightly on the rich
side of the best rpm setting, as a safety measure.
Finally, beyond the normal break-in period, a slight
readjustment toward a leaner needle setting may be
required to maintain maximum performance.

Note:
Please regard the standard positions in the
instruction manual as just a guide. Positions will
vary due to the fuel and silencer used. In general,
if a fuel containing less nitromenthane is used, the
needlevalve will need to be closed further.
Remember, closing the needlevalve too far can
cause rusting and damage to the engine.

CARE AND MAINTENANCE

The minute particles of foreign matter, that are present in

1.
any fuel may, by accumulating and partially obstructing
fuel flow, cause engine performance to become erratic
and unreliable. O.S. 'Super-Filters' (large and small) are
available, as optional extras, to deal with this problem.
One of these filters installed to the pickup tube inside
your refueling container, will prevent the entry of foreign
material into the fuel tank. It is also recommended that a
good in-line filter be installed between the tank and
carburetor.

Do not forget to clean the filters regularly to remove

2.
dirt and lint that accumulate on the filter screens.
Also, clean the carburetor itself occasionally.

At the end of each operating session, drain out any fuel

3.

that may remain in the fuel tank. Afterwards,energize
the glow-plug and try to restart the engine, to burn off
any fuel that may remain inside the engine. Repeat this
procedure until the engine fails to fire. Do this while the
engine is still warm.

Then, inject some after-run oil into the engine, and

4.
rotate the engine with an electric starter for 4 to 5
seconds to distribute the oil to all the working parts.

Note:
Do not inject after-run oil into the carburetor as

this may cause the O-rings inside the carburetor to
deteriorate. These procedures will reduce the risks
of starting difficulties or corrosion after a period of
storage.

5.

Finally, when cleaning the exterior of the engine, use
methanol or a household cleaning agent. Do not use
gasoline, kerosene, or any petroleum based chemical
which can damage silicone fuel tubing.

Dirt and dust may lodge in marked places.

INATALLING DUST CAPS

When storing the engine, install the cap on the exhaust
port, carburetor, etc. to prevent dust from entering the
engine.

CHECKING THE ENGINE

If the engine will not develop normal performance after
long time running due to wearing of parts. It is suggested
to replace necessary parts when the following symptoms
are detected.

Engine sound changes and easily overheats.

Power has dropped extremely.

Idle is unstable and/or engine tends to stop at idle.

In most cases, ball bearings, cylinder & piston assembly,
connecting rod and/or crankcase have become worn.
Check the parts carefully and replace them if necessary.

O.S. GENUINE PARTS & ACCESSORIES

O.S. GLOW PLUG

(71641300)

P3

(71641400)

P4

CARBURETOR REDUCER

(71533255)

5.5

(71533260)

6

(71533265)

6.5

(71533270)

7

CERAMIC REAR BEARING FOR 21

(23730050)

O.S. SPEED CARBURETOR REPAIR KIT 21

(71490000)

O.S. SPEED Carburetor Repair Parts Set 21

(71491000)

O.S. SPEED CARBURETOR
REPAIR PARTS SET 21

(71491000)

O.S. SPEED CLUTCH BEARING (1050ZZ 4pcs.)

(71550001)

O.S. SPEED CLUTCH BEARING (1050ZZ 10pcs.)

(71550002)

O.S. SPEED CILICONE TUBE

(72506100)

2.5mm x 1000mm

O.S. SPEED EXHAUST SEAL RING 21

(22826145)

O.S. SPEED PISTON PIN RETAINER 4mm

(21817010)

O.S. SPEED DUST CAP SET FOR 12-30 CLASS

3mm(2pcs.) / 16mm(2pcs.) / 18mm(1pc.)
(22884254)

DUST CAP SET 3mm

(5pcs.)

(73300305)

DUST CAP SET 16mm

(73301612)

DUST CAP SET 18mm

(73301812)

(3pcs.)

(3pcs.)

(71533280)

8

(71533085)

8.5

(71533290)

9

(71641500)

P5

(10pcs.)

(6pcs.)

M2002SC EXHAUST HEADER PIPE ASSEMBLY

(72106480)

Header Pipe Spring (2pcs.)
Exhaust Seal Ring (2pcs.)

T-2060SC WNI TUNED SILENCER COMPLETE SET

(72106137)

Exhaust Seal Ring (2pcs.)
Joint Spring (3pcs.)
Header Pipe Spring (2pcs.)

(72101272)

(22826140)

(22826140)

(72106042)

(72101272)

T-2090SC TUNED SILENCER COMPLETE SET

(72106192)

T-2090SC Tuned Silencer Assembly

(72106190)

Exhaust Seal Ring (2pcs.)
Joint Spring (3pcs.)

M2000SC Exhaust Header Pipe Assembly

(72106440)

Header Pipe Spring (2pcs.)
Exhaust Seal Ring (2pcs.)

(22826140)

(72106042)

(72101272)

(22826140)

28XZ HYPER FLYWHEEL SET

(For MUGEN)

28XZ Hyper Flywheel MUGEN

(71812100)

Collet

(For KYOSHO)

28XZ Hyper Flywheel KYOSHO

(71813100)

Collet

SUPER AIR CLEANER 203

(72413000)

203 Filter Element (4pcs.)

(72413200)

SUPER AIR CLEANER 204

(72415000)

204 Filter Element (4pcs.)

(72415200)

O.S. SPEED CLUTCH WRENCH & ADJUSTER

(71415300)

O.S. SPEED FLYWHEEL KEY

(71415200)

O.S. SPEED FLYWHEEL PULLER

(71415100)

O.S. SPEED PLUG WRENCH

(71520100)

O.S. SPEED DRIVER TOOLS

Code No.

71410150
71410200
71410250
71410300
71411200
71411250
71412300
71413550
71413600
71413700

Code No. Description

71414015
71414020
71414025
71414030
71414120
71414125
71414230
71414355
71414360
71414370

The specifications are subject to alteration for improvement
without notice.

O.S. SPEED HEX WRENCH TIP ONLY 1.5

O.S. SPEED HEX WRENCH TIP ONLY 2.0

O.S. SPEED HEX WRENCH TIP ONLY 2.5

O.S. SPEED HEX WRENCH TIP ONLY 3.0

O.S. SPEED HEX BALL WRENCH TIP ONLY 2.0

O.S. SPEED HEX BALL WRENCH TIP ONLY 2.5

O.S. SPEED FLAT HEAD SCREWDRIVER TIP 3.0

O.S. SPEED NUT DRIVER TIP ONLY 5.5

O.S. SPEED NUT DRIVER TIP ONLY 6.0

O.S. SPEED NUT DRIVER TIP ONLY 7.0

(71812000)

(71801100)

(71813000)

(71801100)

Description

O.S. SPEED HEX WRENCH DRIVER 1.5

O.S. SPEED HEX WRENCH DRIVER 2.0

O.S. SPEED HEX WRENCH DRIVER 2.5

O.S. SPEED HEX WRENCH DRIVER 3.0

O.S. SPEED HEX BALL WRENCH DRIVER 2.0

O.S. SPEED HEX BALL WRENCH DRIVER 2.5

O.S. SPEED FLAT HEAD SCREWDRIVER 3.0

O.S. SPEED NUT DRIVER 5.5

O.S. SPEED NUT DRIVER 6.0

O.S. SPEED NUT DRIVER 7.0

ENGINE EXPLODED VIEW

Type of screw

C...Cap Screw

5-3

7

8

CARBURETOR EXPLODED VIEW

1

1-1

THREE VIEW DRAWING

Dimensions (mm)

Specifications

Displacement

■

Bore

■

Stroke

■

■

PracticalR.P.M.

■

Output

■

Weight

3.49 cc (0.213 cu.in.

16.27 mm (0.641 in.

16.8 mm (0.661 in.
3,000-41,500 r.p.m.

2.6 ps / 2.56 hp / 34,000 r.p.m.
362 g (12.77 oz.)

6

5-2

)

31.6

45

)

)

2

9

2-1

3

C.M3x18

3

4

5-1

5-4

7-1

Type of screw

S...Set Screw

S.M3x3

1

2

10

4

9

5

11

C.M2.6x18

5

5-1

9-1

10

11

UNF1/4-28

29.5

ENGINE PARTS LIST

16mm

Description

(2pcs.)/

18mm (1pc)

Code No.

No.

22414040

1

22424104

2

22014160

3

22014170

4

22423110

5

22423100

5-1

22016000

5-2

21817010

5-3

22425000

5-4

22282000

6

23981740

7

24881824

7-1

23731020

8

22411030

C.M2.6x7

9
10
11
12
13

23730020
22412010
23107100
22417100
71641300

13

12

22826140

22884254

The specifications are subject to alteration for improvement without notice.

CAP SCREW SETS

Code No.

79871020

M2.6x7

79871055

M2.6x18

79871180

M3x18

Outer Head
Inner Head
Head Gasket (0.2mm)
Head Gasket (0.1mm)
Built-up Parts Set
Cylinder & Piston Assembly
Piston Pin
O.S. SPEED Piston Pin Retainer 4mm(6pcs.)
Connecting Rod
Carburetor Complete (Type 22B2)
Carburetor Retainer Assembly
"O" Ring (2pcs.)
Crankshaft Ball Bearing (Front)
Crankcase
Crankshaft Ball Bearing (Rear)
Crankshaft
Cover Gasket
Cover Plate
Glow Plug P3 (Turbo)
Exhaust Seal Ring (2pcs.)
O.S. SPEED Dust Cap Set For 12-30 Class

3mm

(2pcs.)/

(

)

10pcs./set

Size Pcs. used in an engine

Cover Plate Retaining Screw (4pcs.)

Carburetor Retainer Retaining Screw (1pc.)

Cylinder Head Retaining Screw (4pcs.)

CARBURETOR PARTS LIST

Description

6-15 3-Chome Imagawa Higashisumiyoshi-ku
Osaka 546-0003, Japan

http://www.os-engines.co.jp

TEL. [phone]
FAX. [phone]

60092980 011401

8-1

Code No.

No.

1

23818340

1-1

6

6-1

8

28.5

44

20.5

4- 3.3

37

21

27881820

2

23781400

2-1

26381501

3

23981520

4

22848210

5

71533272

5-1

22615000

6

23618197

6-1

46066319

7

22082940

7-1

22082950

8

22848160

8-1

27881820

9

22282100

9-1

23781110

10

29015019

11

23818190

The specifications are subject to alteration for improvement without notice.

86.5

15.6

Copyright 2013 by O.S. Engine Mfg. Co., Ltd. All rights reserved.

Metering Needle Assembly
"O" Ring (2pcs.)
Ball Link No.3
Retaining Screw
Dust Cover
Slide Valve
Carburetor Reducer 7mm (YELLOW)
"O" Ring
Needle Assembly
"O" Ring
Needle Holder Assembly
Fuel Inlet (No.15)
Throttle Stop Screw
"O" Ring
Carburetor Body (w/Thermo Insulator)
Thermo Insulator
Carburetor Rubber Gasket
Carburetor Sealing Washer