INSTALLATION OF THE STANDARD ACCESSORIES

O.S. SPEED B2104 W/22E(B)It is of vital importance, before attempting to operate yourengine, 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 withthe 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 ahighly efficient internal-combustion machine whose
power is capable of harming you, or others, if it ismisused or abused. As owner, you, alone, areresponsible for the safe operation of your engine, so
act with discretion and care at all times. If at somefuture date, your O.S. engine is acquired by anotherperson, we would respectfully request that these
instructions are also passed on to its new owner.
The advice which follows is grouped under twoheadings 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 lessobvious sources of danger, but which, under certain
circumstances, may also cause damage or injury.
ENGINE CONSTRUCTION
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 slighttaper. The piston and cylinder are designed toachieve a perfect running clearance when theyreach operating temperature.
Near TDC

CylinderLiner

PistonCrankshaft
Slight taper

When the engine is cold. When the engine is hot.

NOTES WHEN APPLYING AN ELECTRIC STARTER
Do not over-prime. This could cause ahydraulic 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 toprevent any pumped out fuel from getting into
your eyes.

Model engine fuel is poisonous. Do notallow 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.

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

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.

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

WARNINGS

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 inan 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 OPERATIONABOUT THE WARRANTY
Since this is a special SPEED version, individual
special parts are available only for limited period(one year after finishing the production).
Also, the engine is free of warranty due to damage
and/or wear occurred during running.
While Operating
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 smallchildren.
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
O.S. SPEED B2104 is a factory tuned engine for 1/8
off-road competition, most parts of which are of new
design: outer head, inner head, crankshaft, piston/linerand cover plate.
A thrust plate with surface treatment embedded in the
cover plate reduces friction against a connecting rod toextend its life.
Standard accessories
Glow Plug P3 Turbo head 1piece(Hot Type)

Install the exhaust seal ring
supplied.

The wearing of safety glasses is also strongly
recommended.

For their safety, keep all onlookers (especially smallchildren) well back (at least 20 feet or 6 meters)
when preparing your model for running.
Before starting the engine, always check thetightness of all the screws and nuts especially thoseof joint and movable parts such as throttle arm.
Missing retightening the loose screws and nuts
often causes the parts breakage that is capable ofharming you.
To stop the engine, fully retard the throttle stick andtrim 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 iscommercially 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 procedurereferred to in the RUNNING-IN paragraphs. Please notethat 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 (optional extra)
The connection between the fuel tank and the engine.
2.5mm ID

NOTE: While the Mixture Control Valve and theMetering Valve are set at the standard position
when the engine leaves the factory, readjustment
may be necessary, occasionally to allow forchanges 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.
INSTALLATION OF THE CARBURETOR

ExhaustSeal Ring

As delivered, the engine has its carburetor lightly installedin the intake boss. Secure it as follows.
Rotate the retainer nut gently until it stops.

Put in the carburetor one of carburetor reducers
according to your taste, generally 6 for buggy and6.5 for truggy.
CARBURETOR CONTROLS STANDARD POSITIONS(POSITIONS WHEN THE ENGINE LEAVES THE FACTORY)
Four adjustable controls are provided on thiscarburetor.
Needle Valve

Tighten a further
120-180

Fit the carburetor in the crankcase and align theposition mark to position the carburetor perpendicular
to the crankshaft.

"O" Ring"O" Ring

Retaining Screw

Throttle Stop
Screw
Metering Needle
Mixture Control ValveThe Needle-Valve:
For adjusting air/fuel ratio (air-fuel mixture) at maximum
rpm (fully opened throttle).

1. Loosen the retainer screw, rotate the carburetor to its
correct position and make sure that it is pressed welldown into the intake boss, compressing the rubber
gasket, before retightening screw.

Needle Valve

2. Rotate the retainer screw gently until it stops, thentighten a further 120-180 .
Do not overtighten the screw as this will damage thethermo insulator.

Open
Close
(Counter-clockwise) (Clockwise)Note
Be careful not to damage the O rings whenremoving the carburetor retainer from the engine.
First, remove the retainer Retaining screw, thenpull out each part. Do not push the part in ordamage the O rings.

[Standard Position]
3 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 Mixture Control Valve:
For adjusting acceleration feeling.
(Adjusting range should be within ±1 turn.)[Standard Position]

Flush with the carburetor body.

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 existingholes in the engine mount do not align perfectly withengine mounting lugs, enlarge them slightly with aneedle-file so that screws are in alignment with themounting holes.

Mixture Control Valve

TOOLS

O.S. SPEED PISTON PIN RETAINER PLIERS
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 WRENCHBASIC ENGINE PARTS
Outer Head

Do not allow bottomof crankcase totouch chassis.

Carburetor Body
The Metering Needle:
For adjusting idle and acceleration feeling.
[Standard Position]
One turn screwed in fromthe flush position with theball link body

Chamfer inside edges of bearers.

Metering Needle

Cover Plate[Standard Position]
Approx 0.7mm

Carburetor

Dust Cap 3, 16, 18 1piece each

Crankshaft

Mounting Lugs
Crankcase
Crankshaft Bearing (Front)

Slide Valve
Note:
Sketch shows the carburetor reducer removed.

PRESSURIZED FUEL SYSTEM
It is recommended that a muffler pressurized fuelfeed system be used so that the fuel may be stably
fed to the carburetor.
The following procedure is suitable when a fuelcontaining 30% nitro-methane is used.
1. Set the carburetor controls at the standard positions(positions when the engine leaves the factory.)
2. Switch the transmitter and make sure that eachlinkage moves correctly.
3. Make sure rotating direction of the starter box iscorrect (counter-clockwise seen from the front edgeof the crankshaft), and turn the engine with thestarter box to draw fuel into the engine.
4. Connect a glowplug ignitor to heat the plug and 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. 15-30° from thestandard position.
approx 1mm
Set the throttle opening alittle 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 backagain 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.
6. Remove the glowplug ignitor when the engine iswarmed up and continue running in on a starter box
around 2-3 tanks with full-throttle. Remain the
carburetor setting very rich as long as the engine
does not go into stall.
7. 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 ataround mid speed, the mixture is too rich. Close theneedle-valve 15~30°.
If the engine still stalls, close the metering needle
15~30°. Run the car on the track until one tank offuel has been consumed, then close the needle-valve
very little (within 10°).
8. 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 isclosed too far.
Now the RUNNING-IN (Breaking-in) is completed.

How to stop the engine

The Throttle Stop Screw:
For setting the minimum idle speed:

Carburetor Reducer (RED)
6.5II 1piece each (w/ "O" Ring)

STARTING THE ENGINE & RUNNING-IN ('Breaking-in)
Running- in is a procedure for an engine to comeclose 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 resultin the oil in the fuel becoming gelled and thepiston/liner becoming stuck together.

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.

Ball Link

Carburetor Reducer (RED)6II 1piece each (w/ "O" Ring)

Exhaust Seal Ring 1pieceInstalling the glow plug. Insert P3 plug supplied intoheatsink-head carefully, making sure that it is notcross-threaded before tightening firmly.
(All the O.S. T-Type plugs including the P3 are notsupplied with a washer.)

NOTE

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

To stop the engine, close thethrottle to idle speed and shut it offcompletely with the trim lever on thetransmitter then cut off the fuelsupply by pinching the fuel delivery
tube to the carburetor.

Fuel

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.

Less fuelOpen

More fuel

Close

Less fuel1. NEEDLE VALVE ADJUSTMENT
Run the vehicle (with throttle fully open) over the
longest available straight course a few times toobserve the model’s speed. Return the vehicle to thestarting 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, stopthe vehicle and reopen the Needle-valve 30~45°.
2. METERING NEEDLE ADJUSTMENT
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 andallow it idle for about five seconds, then reopen thethrottle 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 isprobable that the idle mixture is too rich. In thiscase, 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 thethrottle 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, thethrottle 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 boththe needle-valve and metering needle slightly on the richside 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 berequired to maintain maximum performance.
Note:
Please regard the standard positions in the
instruction manual as just a guide. Positions willvary due to the fuel and silencer used. In general,
if a fuel containing less nitromenthane is used, theneedlevalve will need to be closed further.
Remember, closing the needlevalve too far cancause rusting and damage to the engine.
Attention:
It is vitally important to set thethrottle 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 theground) it will rapidly over-heat and may beseriously damaged.
CARE AND MAINTENANCE
1. The minute particles of foreign matter, that are present inany fuel may, by accumulating and partially obstructing
fuel flow, cause engine performance to become erratic
and unreliable. O.S. 'Super-Filters' (large and small) areavailable, 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 foreignmaterial into the fuel tank. It is also recommended that agood in-line filter be installed between the tank andcarburetor.

4. Then, inject some after-run oil into the engine, androtate 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 todeteriorate. These procedures will reduce the risksof starting difficulties or corrosion after a period ofstorage.

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 inmarked places.

ENGINE PARTS LIST
No. Code No.

Type of screw
C...Cap Screw

C.M3x18

TB01 EFRA2042 (T-2060SC WN)TUNED SILENCER COMPLETE SET (72106135)
TB02 EFRA2089 (T-2090SC)
TUNED SILENCER COMPLETE SET (72106192)

1

TB03 EFRA2155 (T-2100SC)
TUNED SILENCER COMPLETE SET (72107700)
MB01-75(M2000SC) EXHAUST HEADER PIPEASSEMBLY (72106440)

2-1

MB01-80(M2002SC) EXHAUST HEADER PIPEASSEMBLY (72106480)

34MB01-85(M2004SC) EXHAUST HEADER PIPEASSEMBLY (72106910)

12

4-3
4-2

SUPER AIR CLEANER 203 (72413000)
203 Filter Element (4pcs.) (72413200)

4-4

5

11
10

PRESSURE CHAMBER SET (71550000)
O.S. SPEED CARBURETOR REPAIR KIT 21(71490000)
O.S. SPEED Carburetor Repair Parts 21(71491000)
REMOVING DIRT/STAIN

INATALLING DUST CAPS
When storing the engine, install the cap on the exhaust
port, carburetor, etc. to prevent dust from entering theengine.
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.
A notice when you fit the thrust plate to the coverplate again after disassembling the unit.
Do not tighten the nylon nut too much otherwise the thrust
plate is deformed at the center.Press the thrust plate to
the cover plate and tighten the nylon nut until it contacts
to the rear cover, then tighten only 5 degrees clockwise.

O.S. SPEED OFF-ROAD 4-SHOE CLUTCH SYSTEM(71814001)
O.S. SPEED CLUTCH SHOE STANDARD(B)PL(YELLOW) (71814330)
O.S. SPEED CLUTCH SHOE HARD(B)PL(BLACK) (71814340)

O.S. GENUINE PARTS & ACCESSORIES
O.S. GLOW PLUG
P3 (71641300) P4 (71641400)

P5 (71641500)

O.S. SPEED T-SERIES PLUG (24 gold-plated)
P3 (71642720) P4 (71642730)
CARBURETOR REDUCER
6II (71533261)
6 (71533260)
6.5II (71533865)
6.5 (71533265)
8 (71533280)
7 (71533270)
9 (71533290)
8.5 (71533085)
TB03 EFRA2155 (T-2100SC) TUNED SILENCERCOMPLETE SET (72107710)
Exhaust Seal Ring (2pcs.) (22826140)
Joint Spring (3pcs.) (72106042)

No. Code No.

S.M3x3

5

3
2

5-1

3-1
6
6-1
7-1

4

8-2

9

DUST CAP SET 3mm (5pcs.) (73300305)
DUST CAP SET 16mm (3pcs.) (73301612)

9-1

DUST CAP SET 18mm (3pcs.) (73301812)

10

O.S. SPEED PLUG WRENCH (71520100)

1
1-1
2
3
3-1
4
5
5-1
6
6-1
7
7-1
8
8-1
8-2
9
9-1
10

C...Cap Screw S...Set Screw

O.S. SPEED DUST CAP SET FOR 12-30 CLASS
3mm(2pcs.) / 16mm(2pcs.) / 18mm(1pc.)(22884254)

O.S. SPEED PHILLIPS SCREW DRIVER
No.1 (71417100)

surface

1-1

THREE VIEW DRAWING

Size

Pcs. used in an engine

CARBURETOR PARTS LIST

O.S. SPEED EXHAUST SEAL RING 21 (10pcs.)(22826145)

O.S. SPEED CLUTCH WRENCH & ADJUSTER(71415300)

Code No.

79871020 M2.6x7 Cover Plate Retaining Screw (4pcs.)
79871055 M2.6x18 Carburetor Retainer Retaining Screw (1pc.)
79871180 M3x18 Cylinder Head Retaining Screw (4pcs.)

6-1

Type of screw

1

Description
Outer HeadInner HeadInner Head "O" Ring (BLACK)Head Gasket (0.1mm, 0.15mm)
Built-up Parts Set
Cylinder & Piston Assembly
Piston Pin
O.S. SPEED Piston Pin Retainer 2 (6pcs.)
Connecting Rod (w/piston pin retainers 3pcs.)
Carburetor Complete Type 22E(B)Carburetor Retainer Assembly"O" Ring (2pcs.)
Ball Bearing (Front)
Crankcase
Ceramic Bearing (Rear)
Crankshaft
Cover Gasket
Cover Plate Assembly
Thrust Plate (w/ nylon nut M3 BLACK)Glow Plug P3
Exhaust Seal Ring
Carburetor Reducer 6II (RED) w/ "O" Ring
Carburetor Reducer 6.5II (RED) w/ "O" Ring
Dust Cap Set ( 3, 16, 18)

CAP SCREW SETS (10pcs./set)

C.M2.6x18

CARBURETOR EXPLODED VIEW

O.S. SPEED CILICONE TUBE
(72506100) 2.5mm x 1000mm

O.S. SPEED FLYWHEEL PULLER (71415100)
Nylon nut

9

7
8

O.S. SPEED CLUTCH BEARING (1050ZZ 10pcs.)(71550002)

O.S. SPEED FLYWHEEL KEY (71415200)
Thrust plate

6

O.S. SPEED CLUTCH BEARING (1050ZZ 4pcs.)(71550001)

O.S. SPEED PISTON PIN RETAINER PLIERS(71492000)

C.M2.6x7

12-1

4-1

MB01-90(M2005SC) EXHAUST HEADER PIPEASSEMBLY (72106920)

SUPER AIR CLEANER 204 (72415000)
204 Filter Element (4pcs.) (72415200)

Dirt and stain stuck on the engine and silencer/manifold
cause lowering heat dissipation effect. When dirt andstain are detected, remove the engine from the chassis
and clean it with alcohol.

2

1 2DA04000
2 2DA04100
2-1 2DA04180
3 2A004160
4 2DA03010
4-1 2DA03000
4-2 22016000
4-3 2AP17000
4-4 22425003
5 2BP81000
6 23981740
6-1 24881824
7 23731020
8 2DA01000
9 23730050
10 2DA02000
11 23107100
12 2DA07000
12-1 2DA07010
71641300
22826140
71533261
71533865
22884250

78-1
82BN81430
26381501
2BN81520
23818340
27881820
22848210
23618197
46066319
22082940
22082950
22848160
27881820
23781600
46066319
22781800
2BP81100
2AN81101
29015019

Description
Ball Link No.6
Retaining Screw
Dust Cover
Metering Needle Assembly"O" Ring (2pcs.)
Slide Valve
Needle Assembly"O" Ring (2pcs.)
Needle Holder Assembly
Fuel Inlet (No.15)
Throttle Stop Screw"O" Ring (2pcs.)
Mixture Control Valve Assembly"O" Ring (L) (2pcs.)"O" Ring (S) (2pcs.)
Carburetor Body (w/Thermo Insulator)
Thermo Insulator
Carburetor Rubber Gasket

4- 3.3

Dimensions (mm)SPECIFICATIONS
Displacement
Bore
StrokeOutputPractical R.P.M.
Weight3.49 cc / 0.213 cu.in.
16.27 mm / 0.641 in.
16.80 mm / 0.661 in.
2.68 ps / 2.64 hp / 34,000 r.p.m.
4,000-42,000 r.p.m.
352 g / 12.42 oz. (Engine)

37

More fuel

Close

ENGINE EXPLODED VIEW

21

O.S. SPEED PHILLIPS SCREW DRIVER
No.2 (71417200)
O.S. SPEED SPRING REMOVER (71415500)
O.S. SPEED BODY REAMER (71415400)
81.2

Open

3. At the end of each operating session, drain out any fuelthat 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 thisprocedure until the engine fails to fire. Do this while theengine is still warm.

MB01-80(M2002SC) EXHAUST HEADER PIPEASSEMBLY (72106480)
Header Pipe Spring (2pcs.) (72101272)
Exhaust Seal Ring (2pcs.) (22826140)

O.S. SPEED DRIVER TOOLS

Code No.

71410150
71410200
71410250
71410300
71411200
71411250
71412300
71413550
71413600
71413700

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

UNF1/4-28

27

Needle Valve

Metering Needle

2. Do not forget to clean the filters regularly to remove
dirt and lint that accumulate on the filter screens.
Also, clean the carburetor itself occasionally.

15.7

CARBURETOR ADJUSTMENT

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

31.6
45

The specifications are subject to alteration for improvement without notice.

29.5

65.5

6-15 3-Chome Imagawa Higashisumiyoshi-ku
Osaka 546-0003, Japan TEL. (06)6702-0225
http://www.os-engines.co.jp
FAX. (06)6704-2722

Copyright 2021 by O.S. Engines Mfg. Co., Ltd. All rights reserved. Printed in JAPAN.

60093780

092101