O.S. Engines FS-26S-CX User Manual

It is of vital importance, before attempting to
operate your engine, to read the general

'SAFETY INSTRUCTIONS AND WARNINGS'

section on pages 2-5 of this booklet 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.

●

Keep these instructions in a safe place so that
you may readily refer to them whenever
necessary.

●

It is suggested that any instructions supplied
with the vehicle, radio control equipment, etc.,
are accessible for checking at the same time.

CONTENTS

SAFETY INSTRUCTIONS AND WARNINGS
ABOUT YOUR O.S. ENGINE

BASIC ENGINE PARTS
ENGINE INSTALLATION
AIR CLEANER TYPE 101
NOTES CONCERNING THE RECOIL STARTER
GLOWPLUG
TOOLS, ACCESSORIES, etc.
PRESSURIZED FUEL SYSTEM
STARTING,

RUNNING AND ADJUSTMENT
IF THE ENGINE FAILS TO START

11~12

13

2~5

10

12

~

16
16

VALVE ADJUSTING
CARE & MAINTENANCE

6

PARTS REPLACEMENT

7

GENUINE PARTS & ACCESSORIES

8

FS-26S-C EXPLODED VIEW
& PARTS LIST

9

FS-26S-CX EXPLODED VIEW
& PARTS LIST

CARBURETTOR EXPLODED
VIEW & PARTS LIST

THREE VIEW DRAWING

1

17~19
19~20

20
21

22

~

23

24

~

25

26

27~28

SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE

Remember that your engine is not a "toy", but a highly efficient internal­combustion machine whose power is capable of harming you, or others, if it is
misused.
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 applies basically to ALL MODEL ENGINES and 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.

2

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.

•

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.

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.

3

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.

Fit an effective silencer (muffler).

•
Frequent close exposure to a noisy
exhaust (especially in the case of the
more powerful high-speed engines)
may eventually impair your hearing
and such noise is also likely to cause
annoyance to others over a wide area.

NOTES

•

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.

4

•

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

Do not attempt to disassemble the

•
recoil starter of the 12CV-X.
If you do so, the very strong spring
inside will be suddenly ejected. This
can be very dangerous.

Do not extend the starter cord more

•
than 45cm (18"). Do not abruptly
release the operating handle. Allow
the cord to rewind smoothly while
still holding the handle.

NOTES

•

Pull the operating handle straight out
when starting the engine, so that the
cord does not rub against the vehicle
body or engine. This will help prevent
the cord from being damaged by
abrasion or engine heat.

•

Warning! Immediately after a glowplug­ignition 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.

5

INTRODUCTION

These are overhead-valve four-stroke-cycle
engines designed for 1/10 scale radio­controlled model cars. They are based on the
latest version of the well-established FS-26S
aircraft engine, incorporating many improved
or purpose designed parts, including a
special crankshaft, revised camshaft,
stronger valve-springs and new carburettor
with short straight through inlet tract to the
combustion-chamber for improved breathing.
The engine is distinguished by a black­anodized crankcase and rocker-cover and is
supplied complete with an O.S. Super Air
Cleaner as standard.
The FS-26S-CX is equipped with a built in
recoil starter system which eliminates the
need for a separate electric starter and
starter battery.

BASIC ENGINE PARTS

FS-26S-CX

Cylinder Head

Starter
Handle

Crankcase

Beam Mount

6

Rocker Cover

Intake Pipe

Carburettor
Type 1AB-K6

Recoil Starter
Assembly No.5

INSTALLING THE GLOWPLUG

Install the washer on the
glowplug and insert carefully into
cylinder-head, making sure that
it is not cross-threaded before
tightening firmly.

Glow plug

Washer

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

Chassis

Chamfer inside edges of bearers.

mounting lugs, enlarge them slightly with a needle­file so that screws enter vertically. Avoid forcing the
screws. Secure with locknuts. If the bottom of the
recoil starter housing would otherwise touch the car
chassis, install the engine mount spacers
(supplied) between the engine's mounting lugs and
the engine mount. Use the M3x15 screws provided.
With some vehicles, it may be necessary to make
minor trimming modifications to chassis or body
when fitting the engine.

NOTE:

Where spacers are supplied joined in pairs
(see sketch), separate them as shown.
Either face may be placed downwards.

Mount Spacer

Separate

Engine Mount

Engine Mount Spacer

7

AIR CLEANER TYPE 101

This is a heavy-duty wet type air cleaner that has
been developed specifically for O.S. model car
engines. It contains specially impregnated filter
elements which prevent highly damaging dust and
dirt from being drawn into the engine through the
carburettor, yet allow engine performance to be
maintained for longer periods between element
renewals. The Type 101 air cleaner has a special
rubber body which facilitates easy yet secure
fitting, with positive sealing at the carburettor air
intake.

INSTALLATION OF AIR CLEANER

¡

Carefully clean the carburettor, removing any old
adhesive or sealant that may have been
previously used on the outside of the air intake.

¡

Press the air cleaner body firmly over the
carburettor air intake. Make sure that the outer rim
of the intake engages the internal annular groove
in the air cleaner: failure to do so may result in the
air cleaner falling off. See sketch, right.

FILTER ELEMENTS

¡

The elements are already impregnated with a
special filter oil. As this oil is very sticky, take
care, when handling it, to prevent dust or dirt
from adhering to the elements. If your fingers
become contaminated, wash them with soap
and water.

¡

During storage, the oil may have become
unevenly dispersed through the elements.
This will be indicated if
element material appears patchy.
place the elements in a small plastic bag and
gently rub them between finger and thumb to
redistribute the oil.

Lower Filter
Element

8

the blue color of the

In this case,

Upper Filter
Element

Insert beneath flanges.

REPLACEMENT OF ELEMENTS

It is advisable to replace the upper filter element
with a new one after not more than one hour of
running time. It is not necessary to discard the
lower element as frequently, but be sure to
change it when it becomes soiled. Always
remove contaminated elements carefully, to
ensure that dirt cannot enter the carburettor.

NOTES CONCERNING THE RECOIL STARTER

REMINDER!

Do not attempt to disassemble the recoil

◆

starter. If you do so, the very strong spring
inside will be suddenly ejected. This can be
very dangerous.
Do not extend the starter cord more than

◆

45cm(18"). Do not abruptly release the
operating handle. Allow the cord to rewind
smoothly while still holding the handle.

◆

Pull the operating handle straight out when
starting the engine, so that the cord does
not rub against the vehicle body or engine.

( FS-26S-CX ONLY)

◆

This will help prevent the cord from being
damaged by abrasion or engine heat.

Try to avoid spilling fuel over the starter unit

◆

and its cord. Some fuels have a detrimental
effect on these parts.

◆

The starter prevents the engine from being
rotated in the wrong direction. The unit will
be damaged if you attempt to force the
flywheel in the opposite direction (i.e.
clockwise when viewed from the crankshaft
end).

NOTE:
Because, in the interests of personal safety,
dismantling of the starter mechanism is
strongly discouraged, the Recoil Starter is
available for replacement only as a pre­assembled unit. However, some related parts,
such as Starting Shaft and Rear Adaptor, are
obtainable separately. (See Parts List.)

9

GLOWPLUG

The FS-26S-C and FS-26S-CX are supplied with
an O.S. Type F glowplug, specially designed for
O.S. four-stroke engines.

The role of the glowplug

With a glowplug engine, ignition is initiated by
the application of a 1.5-volt power source. When
the battery is disconnected, the heat retained
within the combustion chamber remains
sufficient to keep the plug filament glowing,
thereby continuing to keep the engine running.
Ignition timing is 'automatic' : under reduced
load, allowing higher rpm, the plug becomes
hotter and, appropriately, fires the fuel/air charge
earlier; conversely, at reduced rpm, the plug
become cooler and ignition is retarded.

Glowplug life

Particularly in the case of very high performance
engines,
expendable items.

glowplugs must be regarded as

However, plug life can be extended and engine
performance maintained by careful use, i.e.:

Install a plug suitable for the engine.

•

Use fuel containing a moderate percentage of

•

nitromethane unless more is essential for
racing events.

Do not run the engine too lean and do not

•

leave the battery connected while adjusting the
needle.

When to replace the glowplug

Apart from when actually burned out, a plug may
need to be replaced because it no longer
delivers its best performance, such as when:

Filament surface has roughened and turned

•

white.
Filament coil has become distorted.

•

Foreign matter has adhered to filament or plug

•

body has corroded.
Engine tends to cut out when idling.

•

Starting qualities deteriorate.

•

10

TOOLS, ACCESSORIES, etc.

The following items are necessary for operating
the engine.

FUEL

Use only top quality methanol-based model engine
fuel.For consistent performance and long engine
life, it is advisable to use fuel containing A T LEAST
18% lubricant. This engine is designed to run on
both low and high nitromethane content fuels,i.e.
from mild mixtures containing small percentage of
nitromethane, up to high-speed racing fuels
containing 40% nitromethane. Generally, power
output is increased-up to a certain
nitromethane content of the fuel is increased.
starting point, we recommend a fuel containing 10­20% nitromethane, changing to a fuel containing
more nitro only if necessary. When the nitro content
of the fuel is increased or the brand of fuel is
changed, it is advisable to initially run the engine
with a richer needle-valve setting, so that the
optimum setting for the new fuel may be rechecked

point-as the

As a

rechecked as described in the RUNNING-IN
paragraphs. When engines are run at very high
speeds and on high-nitro fuels, glowplug elements
will not last as long.

Reminder!

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.

BATTERY INTEGRATED GLOWPLUG HEATER

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

11

ELECTRIC STARTER AND STARTER BATTERY

Use a 12-volt electric starter
with suitable battery for starting
the engine.(FS-26S-C)

LONG SOCKET WRENCH

Recommended for easy removal
and replacement of the angled
and recessed glowplug, the
O.S.Long Socket Wrench
incorporates a special grip.

FUEL PUMP

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

SILICONE FUEL LINE

Heatproof silicone tubing of
approx. 5mm o.d. and 2mm i.d.
is required for the connection
between the fuel tank and
engine.

PRESSURIZED FUEL SYSTEM

●

The somewhat violent changes of vehicle
attitude that occur in off-road running,
combined with the fact that, in buggy type
cars, the fuel tank is often located some
distance from the carburettor, means that fuel
'head' at the carburettor can vary and upset
running.Therefore,it is recommended that a
muffler pressurized fuel feed system be used.

●

Never run your vehicle without the air cleaner.
Dust and dirt that may otherwise be drawn into
the engine will rapidly shorten its life.

Fuel Tank

12

Connect suitable length of
Silicone tubing between fuel
tank and silencer.

Silencer

Silicone tubing

ST ARTING, RUNNING AND ADJUSTMENT

In the interests of a long working life and high
performance, every internal-combustion engine
needs to be "run-in" (or "broken-in" as the
procedure is also known). This means giving the
engine extra care and attention during the first
hour or so of its operational life. New parts need
to become "bedded-in", i.e. smoothed and
aligned to reduce friction and avoid distortion.
For this to take place, the engine must not be
overloaded or run too fast. The essential
ingredients here, are ample lubrication and
cooling. Such a condition is achieved by having
the engine operate on an extremely rich needle­valve setting : the excess oil not only provides an
abundance of lubrication; it also conducts away
heat from the surrounding metal and this is
further assisted by the partial evaporation of the
alcohol content of the fuel.

13

With an aircraft engine, cooling is also aided, in
large measure, by the slipstream and some
model car enthusiasts elect to carry out initial
running-in, in this way by bench-mounting the
engine and temporarily fitting it with an aircraft
type drive hub and propeller. In the case of the
O.S. FS-26S-C, however, the fact that it is a four­stroke engine with inlet pipe and carburettor
mounted high on the cylinder-head, means that
each charge of rich, cooling, fuel-air mixture is
admitted directly into the cylinder, instead of
being pre-heated in a lengthy journey via the
crankcase, as in the usual two-stroke model car
unit. With extra care, the FS-26S-C can,
therefore, be run-in ready-installed in the car.

●

Turn the needle-valve gently clockwise until it
stops. Do not use force to turn the needle
beyond this point. Now reopen it 2 turns.

●

Set the throttle-stop screw
so that the minimum

1.5mm

throttle opening (idle
setting) is approximately

1.5mm.

●

Switch on the transmitter, followed by the
receiver. Close the throttle stick and open the
throttle trim lever to the idle setting.

●

Connect the glowplug battery and apply the
electric starter. As soon as the engine starts,
disconnect the glowplug battery, keeping the
engine running slowly on the rich needle set­ting. (If necessary, make a slight readjustment
to the throttle stick to keep the engine idling
steadily.) If the engine stops, allow it to cool for
a minute or two before restarting it. In fact, short
runs, interrupted by brief cooling-off periods is
good practice during running-in.

Front

Rotating Direction

Rear

■

When the FS-26S-CX is installed in certain
ready-to-run cars:

●

Press choke button on car's fuel tank
sufficient to prime carburetor.
(Do not overprime!)

●

Making sure that
glowplug remains
switched off, check
that starter handle can
be pulled out, then re­connect plug and
operate starter briskly
until engine starts.

Starter Handle

14

Note!
Four stroke engine have stronger
compression than two stroke engines.
Hold the chassis firmly when pulling the
recoil starter. Also, wearing of gloves is
recommended to avoid any risk of injury.

Remember!

It is vitally important to set
the throttle at the correct
position before attempting
to start the engine. If the
engine is allowed to run
with the throttle too far
open under "no load"
conditions, it will rapidly overheat and may be
seriously damaged.

●

Now, refuel and re-start the engine, opening
the throttle just sufficiently to engage the
centrifugal clutch and allow the car to run on
the track without stalling and still with the
needle-valve set rich to promote cool
running.

15

●

After running the engine for four or five tanks
of fuel, begin closing the needle a few degrees
(1 to 3 cllicks) between succeeding runs. Also,
vary its speed, from idling to medium RPM,
with the throttle. See sketch.

●

Eventually, the engine will begin to loosen up
sufficiently to allow short bursts of full-throttle
acceleration with the needle-valve at its
optimum setting.

Note!
Do not close the needle-valve any further. If
you do so, the engine will begin to overheat
and the car will slow down, accompanied by
visibly diminished exhaust smoke. In this
event, bring the vehicle to a halt immediately
and reopen the needle-valve 20° to 30°.

●

Now open the needle-valve 20°-30° from the
setting at which the highest straight line
speed is obtained. This slightly rich setting
should provide the optimum balance. Run
the car for about three more tanks of fuel to
allow fine-tuning of any final adjustments.

The position of the
needle-valve when

30˚

starting the engine.

Needle Slot
The position of the
needle-valve where
highest speed of
the vehicle is
obtained.

●

To stop the engine, close the throttle to idling

20˚

~

30˚

Optimum needle-valve position (20° to 30° opened
from the position where highest speed of the vehicle
is obtained.)

30˚

30˚

Close the needle-valve
approx. 30° after
running the vehicle for
one full tank of fuel.
Repeat this procedure
several times.

speed, then shut it off completely with the
trim lever on the transmitter. To cut off the
fuel supply, pinch the fuel delivery tube to the
carburettor.

IF THE ENGINE FAILS TO START

●

Check the following:

●

Glowplug battery discharged or glowplug
defunct.

●

Fuel not reaching carburettor.

●

Engine flooded. Do not over-prime. (This
could also cause hydraulic lock and damage

the engine on application of the electric
starter.) Remove glowplug, close needle­valve and apply starter to pump out surplus
fuel. (Cover the plug hole with a foided cloth,
so that fuel cannot spiash into your face.)

For 26S-CX

16

VALVE ADJUSTING

ALL O.S. four-stroke engines have their
valve(tappet) clearances correctly set before
they leave the factory. However, if, after many
hours of running time have been logged, a loss
of power is detected, or if the engine has to be
disassembled or repaired as a result of an
accident, valve clearances should be checked
and readjusted, as necessary. O.S. Valve
Adjusting Tool Kit is available as optional
accessory.

The kit comes in a plastic case and includes:
(Code No.72200060)

• Feeler gauge 0.04mm

• Feeler gauge 0.1mm

• Hex. key 1.5mm

Note:
Valve clearances of all O.S. four-stroke­cycle engines must be checked and reset
ONLY WHEN THE ENGINE IS COLD.
Procedure is as follows.

• Wrench 5mm

• Screwdriver

(1)

Remove the cover from the rocker-box on

1.
top of the cylinder-head, using the correct
size Allen hex key.

Turn the flywheel counter-clockwise until

2.
compression is first felt, then turn it a further
quarter revolution. At this point, both valves
should be closed. (If the prop driver ('drive
hub') of your engine is engraved with a letter
'T', this mark should now be at the top.)

3.

The standard valve clearance, on both inlet
and exhaust valves, is between 0.04mm and

0.10mm(0.0015-0.004 inch), measured
between valve stem and rocker arm. Use the

0.04mm and 0.10mm feeler gauges to check
clearances.
(See Fig.1.)

17

0.04mm Feeler Gauge
Rocker Arm

Valve

Fig.1

Note:
If the gap is found to be less than 0.04mm,
it is not necessary to readjust the clearance
if the engine has good compression and
starts easily. Equally, if the gap exceeds

0.10mm but is not more than 0.14mm (i.e.
the thickness of both feeler gauges inserted
together), it is not essential to readjust the
clearance if the engine runs satisfactorily.

(2)

If a clearance is found to be outside either of
these limits, it should be reset as follows.

1.

Carefully loosen locknut on rocker-arm 1/4­1/2 turn with a 5mm wrench. (Fig.2.)

Locknut

Slacken approx. 1/4 to 1/2 turn.

Wrench

2.

Turn adjusting-screw approx. 1/2 turn counter­clockwise to open gap, using appropriate tool ­i.e. Allen hex key. (Fig.3.)

Adjusting Screw

3.

Insert 0.04mm feeler gauge between valve

Turn approx.
1/2 turn.

Allen Key

stem and rocker-arm and gently turn adjusting
screw clockwise until it stops.(Fig.4.)

Turn with fingers
until it stops.

0.04mm Feeler Gauge

Fig.3

Fig.2

Fig.4

18

Re-tighten locknut while holding adjusting

4.
screw stationary. (Fig.5.)

Hold at the screw head.

Fig.5

5.

Remove 0.04mm feeler, rotate the

Tighten Locknut.

crankshaft through two revolutions and
recheck gap.

If clearance is correct, slacken locknut on

6.
the other rocker-arm and repeat steps 1 to 5
above. Finally, replace rocker box cover.

Remember:
Excessive valve clearance will cause loss of
power, due to valve (s) not opening
sufficiently. On the other hand, a total loss of
clearance may cause difficult starting due to
valves not closing properly, resulting in loss
of compression.

CARE & MAINTENANCE

●

At the end of each operating session, drain
the fuel tank, then energize the glowplug and
try to re-start the engine to burn off any fuel
that may remain inside. Repeat this
procedure until the engine fails to fire. Then
remove the glowplug and drain off any
residue while the engine is still warm.

●

Inject some corrosion-inhibiting after-run oil
and rotate the crankshaft to distribute oil to
the working parts. Do not inject such oil into
the carburettor, however, as it may cause
deterioration of the carburettor's O-ring seals.

●

Apply a little lubricating oil to the rocker shaft
and rocker arms.

Note!
These maintenance procedures will reduce
the risks of corrosion or starting difficulties
after a period of storage.

19

●

When cleaning the exterior of the engine,
use methanol or kerosene. Do not use
gasoline or any solvent that might damage
the silicone fuel tubing.

PARTS REPLACEMENT

●

Over a long period, depending on how well
your engine has been protected from the
ingress of dust and grit and other causes of
wear and tear, loss of performance may
eventually occur in the form of reduced
power, reluctant starting, unstable idling, etc.
Having checked that this is not due merely to
the need to readjust the valve clearances (for
which an O.S. Valve Adjustment Kit - Code
No. 72200060 - is available) inspection may
then reveal that the replacement of some
parts may be called for.
Contact the O.S. distributor in your country
for parts or full service. See pages 21 of this
booklet for details of parts.

20

GENUINE PARTS & ACCESSORIES

RACING ENGINE PARTS

O.S.Glow Plug

■

TYPE F

(71615009)

Super Air Cleaner 101

■

(72403100)

101,102 Filter Elements

■

(72403120)

Hyper Exhaust

■

(44126000)For KYOSHO Super Ten
(44126010)For KYOSHO Pure Ten

Super Joint Tube 15

(72103310)

(6pcs.)

Dust Cap Set

■

φ4

(73300305)

For Carburettor Nipple

φ7

(73300712)

For T-1020 Tuned Silencer

Valve Adjusting Tool Kit

■

(72200060)

■■

T-1020Tuned Silencer

(72103020)

21

F-2000 4C Car Silencer

■

(44125100)

Long Socket Wrench With

■

Plug Grip

(71521000)

FS-26S-C EXPLODED VIEW

C.M2.6X12

C.M2.6X18

2

4

-2

4

4

-1

5

-

0

0

-1

C.M2.6X7

-1

-

9

8

=

-

-2

q

e

w

r

t

u

-1

i

u

o

N.+M3.5X5

22

C.M2.6X7

Type of screw

✽

C…Cap Screw B…Binding Head Screw M…Oval Fillister-Head Screw
F…Flat Head Screw N…Round Head Screw S…Set Screw

y

3

-1

3

3

-2

5

-4

-3

5

-2

5

-1

d

[

p

1

5

7

6

\

a

-2

a

a

-1

a

-2

s

f

C.M2.6X7

]

No. Description

23

Code No.

1

4 4113 000

2

4 5704 210

3

4 5761 400

3

-1

4 5761 410

3

-2

4 5761 600

4

4 5761 000

4

-1

4 5761 100

4

-2

4 5761 200

5

4 5760 020

5

-1

4 5760 110

5

-2

4 5760 210

5

-3

4 5060 309

5

-4

4 6160 400

6

4 4104 100

7

4 4104 020

8

4 5769 200

9

2 1381 950

0

4 4169 400

2 3081 725

0

-1

-

2 1381 050
2 1015 001

-

-1

2 3081 706

-

-2

2 2714 100

=

4 4103 400

q

4 4103 200

w

2 2706 000

e

4 5705 000

r

4 4103 100

t

4 5707 010

y
u

4 4102 010

u

-1

4 5702 100

i

2 2630 002

o

4 4101 010

p

4 5762 100

[

4 5762 010

]

4 5701 110

\

4 4166 000

a

4 4166 100

a

4 4166 110

-1

2 4881 824

a

-2

s

4 5264 000

d

4 5231 000

f

2 3210 007
7 1615 009
7 2403 100
7 2403 110
7 2403 120

Screw Set
Rocker Cover
Rocker Support Assembly
Rocker Support
Rocker Arm Retainer(2pcs.)
Rocker Arm Assembly(1pair)
Rocker Arm(1pc.)
Tappet Adjusting Screw
Valve Assembly(1pair)
Valve(1pc.)
Valve Spring(1pc.)
Valve Spring Seat(1pc.)
Valve Spring Retainer(2ps.)
Cylinder Head
Cylinder Head Assembly
Exhaust Pipe Lock Nut
Insulator
Intake Pipe Assembly
Intake Pipe Retaining Screw(2pcs.)
Carburetor Complete(1AB-K6)
Carburetor Gasket
Carburetor Retaining Screw(2pcs.)
Cylinder Head Gasket
Piston Ring
Piston
Piston Pin
Connecting Rod
Cylinder Liner
Cover Plate
Crankshaft
Crankshaft Spacer
Crankshaft Ball Bearing(Rear)
Crankcase
Thrust Ball(2pcs.)
Camshaft
Cam Cover
Push Rod(2pcs.)
Push Rod Cover Assembly(2pcs.)
Push Rod Cover(1pcs.)
Push Rod Cover “O“Ring(2pcs.)
Cam Follower(2pcs.)
Crankshaft Ball Bearing(Front)
Propeller Nut
Glow Plug Type F
Super Air Cleaner 101(W/3 filter elements)
101 Cleaner Body
101,102 Filter Element(6pcs.)

Specifications are subject to alteration for improvement without notice.

FS-26S-CX EXPLODED VIEW

C.M2.6X12

C.M2.6X18

4

-2

4

4

-1

-

0

0

-1

C.M2.6X7

-1

-

u

9

=

-

-2

i

[

o

-1

p

o

N.+M3.5X5

24

y

C.M2.6X7

y

Type of screw

✽

C…Cap Screw B…Binding Head Screw M…Oval Fillister-Head Screw
F…Flat Head Screw N…Round Head Screw S…Set Screw

-2

-1

y

2

1

3

-1

3

3

-2

5

-4

5

-3

5

-2

5

8

5

-1

q

e

w

r

t

g

]

7

6

s

d

-2

d

d

-1

d

-2

f

h

\

C.M2.6X7

a

Description

25

No.

Code No.

4 4113 000

1

4 5704 210

2

4 5761 400

3

4 5761 410

3

-1

4 5761 600

3

-2

4 5761 000

4

4 5761 100

4

-1

4 5761 200

4

-2

4 5760 020

5

4 5760 110

5

-1

4 5760 210

5

-2

4 5060 309

5

-3

4 6160 400

5

-4

4 4104 100

6

4 4104 020

7

4 5769 200

8
9

2 1381 950

0

4 4169 400

2 3081 725

0

-1

-

2 1381 050

-

2 1015 001

-1

2 3081 706

-

-2

=

2 2714 100

q

4 4103 400

w

4 4103 200

e

2 2706 000

r

4 5705 000

t

4 4103 100

y

7 3003 000

y

7 3003 100

-1

y

7 3003 200

-2

u

4 4121 000

i

4 4121 200

o

4 4102 100

o

-1

4 5702 100

p

2 2630 002
4 4101 020

[

4 5762 100

]

4 5762 010

\

4 5701 110

a

4 4166 000

s

4 4166 100

d

-1

d

4 4166 110

-2

2 4881 824

d

f

4 5264 000

g

4 5231 000

h

2 3210 007
7 1615 009
7 2403 100
7 2403 110
7 2403 120

Screw Set
Rocker Cover
Rocker Support Assembly
Rocker Support
Rocker Arm Retainer(2pcs.)
Rocker Arm Assembly(1pair)
Rocker Arm(1pc.)
Tappet Adjusting Screw
Valve Assembly(1pair)
Valve(1pc.)
Valve Spring(1pc.)
Valve Spring Seat(1pc.)
Valve Spring Retainer(2ps.)
Cylinder Head
Cylinder Head Assembly
Exhaust Pipe Lock Nut
Insulator
Intake Pipe Assembly
Intake Pipe Retaining Screw(2pcs.)
Carburetor Complete(1AB-K6)
Carburetor Gasket
Carburetor Retaining Screw(2pcs.)
Cylinder Head Gasket
Piston Ring
Piston
Piston Pin
Connecting Rod
Cylinder Liner
No.5 Recoil Starter Assembly
No.5 Recoil Starter Body
No.5 One-way Clutch
Rear Adaptor
Starting Shaft
Crankshaft
Crankshaft Spacer
Crankshaft Ball Bearing(Rear)
Crankcase
Thrust Ball(2pcs.)
Camshaft
Cam Cover
Push Rod(2pcs.)
Push Rod Cover Assembly(2pcs.)
Push Rod Cover(1pcs.)
Push Rod Cover “O“Ring(2pcs.)
Cam Follower(2pcs.)
Crankshaft Ball Bearing(Front)
Propeller Nut
Glow Plug Type F
Super Air Cleaner 101(W/3 filter elements)
101 Cleaner Body
101,102 Filter Element(6pcs.)

Specifications are subject to alteration for improvement without notice.

CARBURETTOR EXPLODED VIEW & PARTS LIST

N.+M3X6

2

1

-1

1

✽ Type of screw

C…Cap Screw M…Oval Fillister-head Screw F…Flat Head Screw

…

N

Round Head Screw S…Set Screw

3

N.+M3.5X5

4

7

6

5

-2

No.

Code No.

1

2 2081 408

1

-1 2 2081 313

2

2 1781 200

3

2 2081 811

4

2 1381 130

5

2 1181 902

5

2 1181 976

-1

5

2 1181 967

-2

5

2 1111 300

-3

6

2 1015 001

7

2 3081 706

Specifications are subject to alteration for improvement without notice.

5

-3

5

5

Throttle Lever Assembly
Throttle Lever Retaining Screw
Carburettor Rotor
Throttle Stop Screw
Carburettor Body
Needle-valve Assembly
Needle
Nozzle Assembly
Ratchet Spring
Carburettor Rubber Gasket
Carburettor Retaining Screw (2pcs.)

-1

Description

26

FS-26S-C THREE VIEW DRAWING

Specification

Displacement
Bore
Stroke
Practical R.P.M.
Power output
Weight

4.41cc (0.269cu.in.)

18.5mm (0.728in.)

16.4mm (0.648in.)
2,000

~

22,000r.p.m.

0.5bhp/17,000r.p.m.

242.5g (8.56oz.)

70.4

84.6

43

36

UNF1/4-28

32.8

14

29

27

39.8

18

Dimension(mm)

FS-26S-CX THREE VIEW DRAWING

Specification

Displacement
Bore
Stroke
Practical R.P.M.
Power output
Weight

4.41cc (0.269cu.in.)

18.5mm (0.728in.)

16.4mm (0.648in.)
2,000

~

22,000r.p.m.

0.5bhp/17,000r.p.m.
308g (10.87oz.)

20

70.4

20

28

35.2

14

39.8

Dimension(mm)

36

43

UNF1/4-28

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Copyright 2000 by O.S.Engines Mfg. Co., Ltd. All rights reserved. Printed in Japan.

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

TEL.[phone]

FAX. [phone]

090101