O.S. engine FS-40S-C Setup guide

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.
●
●

SAFETY INSTRUCTIONS AND WARNINGS
ABOUT YOUR O.S. ENGINE
INTRODUCTION, BASIC ENGINE PARTS
INSTALLATION OF THE CARBURETOR
ENGINE INSTALLATION
SUPER AIR CLEANER TYPE 102S
NOTES CONCERNING THE RECOIL STARTER
GLOWPLUG
TOOLS, ACCESSORIES, etc.
PRESSURIZED FUEL SYSTEM
STARTING,
RUNNING AND ADJUSTMENT
IF THE ENGINE FAILS TO START
VALVE ADJUSTING
CARE & MAINTENANCE
PARTS REPLACEMENT
GENUINE PARTS & ACCESSORIES
FS-40S-C EXPLODED VIEW
& PARTS LIST
FS-40S-CX EXPLODED VIEW
& PARTS LIST
CARBURETTOR EXPLODED
VIEW & PARTS LIST
THREE VIEW DRAWING
2 ~ 5
6
7
~ 8
8 ~ 9
9
~ 10
10 ~ 11
11
~ 12
13
13 ~ 16
21
20
27 ~ 28
20
17 ~ 19
22
~ 23
24 ~ 25
26
CONTENTS
17
1

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.
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.
SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE
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 NOTES
These cover events which
might involve serious (in
extreme circumstances, even
fatal) injury.
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
whichmightigniteit.Donot
smokeorallowanyoneelse
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
most 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.
NOTES
•
•
•
•
•
•
4

NOTES
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 tube 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.
•
Do not attempt to disassemble the
recoil starter of the 40S-CX.
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 40cm (16"). 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. This will help prevent
the cord from being damaged by
abrasion or engine heat.
•
5

These are overhead-valve four-stroke-
cycle engines designed for 1/8 scale
radio-controlled model cars.
The engine is distinguished by a black-
anodized crankcase and rocker-cover
and is supplied complete with an O.S.
Super Air Cleaner as standard.
The FS-40S-CX is equipped with a built
in recoil starter system which eliminates
the need for a separate electric starter
and starter battery.
INTRODUCTION
Rocker Cover
Intake Pipe Cylinder Head
Recoil Starter
Assembly Crankcase
Beam Mount
Carburettor
BASIC ENGINE PARTS
Starter Handle
FS-40S-CX
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
6

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 3.5mm 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.
mountinglugs,enlargethemslightlywithaneedle-
filesothatscrewsentervertically.Avoidforcingthe
screws.
INSTALLATION OF THE CARBURETOR
As delivered, the engine has its carburetor lightly
fit into the intake boss. Secure it as follows.
Loosen the retainer screw,and remove the
carburetor. Place the rubber gasket at bottom
of the intake boss, and rotate the carburettor
to its 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 tighten a further 60-90˚.
Do not overtighten the screw as this will
damage the carburettor body.
1.
2.
7

AIR CLEANER TYPE 102S
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 air intake engages the internal
annular groove in the air cleaner: failure to do
so may result in the air cleaner falling off.
•
It has a single filter element and is intended
primarily for circuit racing, where conditions are
less damaging than the very dusty, loose surfaces
of off-road operation for which the double-element
Type101and102AirCleanersarerecommended.
The lower height of the Super Air-Cleaner 102S
also facilitates easier installation in cars where
available space may be restricted.
NOTE:
Where spacers are supplied joined in pairs
(see sketch), separate them as shown.
Either face may be placed downwards.
Secure with locknuts. If the bottom of the recoil
starter housing would otherwise touch the car
chassis, install the engine mount spacers
(supplied)betweentheengine'smountinglugsand
the engine mount. Use the M3.5x15 screws
provided.Withsomevehicles,itmaybenecessary
tomakeminortrimmingmodificationstochassisor
body when fitting the engine.
Mount Spacer
Separate
Engine Mount Engine Mount Spacer
8

◆
NOTES CONCERNING THE RECOIL STARTER
( FS-40S-CX ONLY)
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
40cm(16"). 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.
It is advisable to replace the filter element with
a new one after not more than one hour of
running time. Always remove contaminated
elements carefully, to ensure that dirt cannot
enter the carburettor.
REPLACEMENT OF ELEMENT
•
Position the air cleaner correctly, so that it
does not foul the cylinder-head or obstruct the
needle-valve.
•
FIT THE FILTER ELEMENT
The element is 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 element. If your fingers
become contaminated, wash them with soap
and water.
During storage, the oil may have become
unevenly dispersed through the element. This
will be indicated if the blue colour of the element
material appears patchy.
•
•
Insert beneath flange
In this case, place the
element in a small plastic
bag and gently rub it
betweenfinger andthumbto
redistribute the oil.
9

GLOWPLUG
The role of the glowplug
Glowplug life
Particularly in the case of very high performance
engines, glowplugs must be regarded as
expendable items.
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.
The FS-40S-C and FS-40S-CX are supplied with
an O.S. Type F glowplug, specially designed for
O.S. four-stroke engines.
◆
◆Trytoavoid spilling fueloverthestarter 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 pre-
assembled unit. However, some related parts,
such as Starting Shaft and Rear Adaptor, are
obtainable separately. (See Parts List.)
This will help prevent the cord from being
damaged by abrasion or engine heat.
◆
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 containingAT LEAST18% lubricant. This engine
isdesignedtorunonbothlowandhighnitromethanecontent
fuels,i.e. from mild mixtures containing small percentage of
nitromethane,upto high-speed racingfuels containing 40%
nitromethane. Generally, power output is increased up to
a certain point as the nitromethane content of the fuel is
increased. As a starting point, we recommend a fuel
containing 10-20% 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,itisadvisabletoinitiallyruntheenginewitharicher
needle-valvesetting,sothattheoptimumsettingforthenew
fuel may be rechecked as described in the RUNNING-IN
paragraphs. When engines are run at very high speeds and
on high-nitro fuels, glowplug elements do not last so long.
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.
However, plug life can be extended and engine
performance maintained by careful use, i.e.:
Apart from when actually burned out, a plug may
need to be replaced because it no longer
delivers its best performance, such as when:
When to replace the glowplug
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.
•
•
•
•
•
•
•
•
11

LONG SOCKET WRENCH
Recommendedfor easyremoval
and replacement of the angled
and recessed glowplug, the
O.S.Long Socket Wrench
incorporates a special grip.
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.
ELECTRIC STARTER AND STARTER BATTERY
Use a 12-volt electric starter
with suitable battery for starting
the engine.(FS-40S-C)
FUEL PUMP
For filling the fuel tank, a simple,
polyethylene "squeeze" bottle,
with a suitable spout, is required.
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 awayfromopenflame,
excessive heat, sources of sparks, or
anything else which might ignite it.
Reminder!
BATTERY INTEGRATED GLOWPLUG HEATER
Commercialy available handy
glowplug heater in which the
glowplug battery and battery
leads are integrated.
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.
12

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 needle-
valve 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.
STARTING, RUNNING AND ADJUSTMENT
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.
PRESSURIZED FUEL SYSTEM
●
●
Fuel Tank
Silencer Silicone tubing
Connect suitable length of
Silicone tubing between fuel
tank and silencer.
13

2mm
Turn the needle-valve gently clockwise until it
stops. Do not use force to turn the needle
beyond this point. Now reopen it 1 3/4 turns.
Set the throttle-stop screw
so that the minimum
throttle opening (idle
setting) is approximately
2mm.
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 set-
ting. (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.
●
●
●
●
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-40S-C, however, the fact that it is a four-
stroke 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-40S-C can,
therefore, be run-in ready-installed in the car.
14

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.
Remember!
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.
●
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.
Note!
■
Front
Rear
Rotating Direction
Starter Handle
In case of FS-40S-CX
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 re-
connect plug and operate
starter briskly until engine
starts.
●
Do not extend the starter cord more than
40cm (16").
15

30°
10°
~
20°
30°
30°
Needle Slot
The position of the
needle-valve when
starting the engine.
Close the needle-valve
approx. 30°after
running the vehicle for
one full tank of fuel.
Repeat this procedure
several times.
Optimum needle-valve position (10°to 20°opened
from the position where highest speed of the vehicle
is obtained.)
The position of the
needle-valve where
highest speed of
the vehicle is
obtained.
To stop the engine, close the throttle to idling
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.
●
Re-adjust the throttle stop screw, if
neccessary, so that the car may not move at
idling.
After running the engine for four or five tanks
of fuel, begin closing the needle 5-15 degrees
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.
●
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 10°to 20°.
Note!
Now open the needle-valve 10°-20°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.
●
16

Note:
Valve clearances of all O.S. four-stroke-
cycle engines must be checked and reset
ONLY WHEN THE ENGINE IS COLD.
Procedure is as follows.
• Feeler gauge 0.04mm
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.
VALVE ADJUSTING
The kit comes in a plastic case and includes:
(Code No.72200060)
• Feeler gauge 0.1mm
• Hex. key 1.5mm
• Wrench 5mm
For 40S-CX
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 needle-
valve and apply starter to pump out surplus
fuel. (Cover the plug hole with a foided cloth,
so that fuel cannot spiash into your face.)
●
●
●
●
17

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.
Carefully loosen locknut on rocker-arm 1/4-
1/2 turn with a 5mm wrench. (Fig.2.)
1.
Locknut
Wrench
Slacken approx. 1/4 to 1/2 turn.
Fig.2
Remove the cover from the rocker-box on
top of the cylinder-head, using the correct
size Allen hex key.
1.
(1)
Turn the flywheel counter-clockwise until
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.)
2.
The standard valve clearance, on both inlet
and exhaust valves, is between 0.04mm and
0.14mm(0.0015-0.005 inch), measured
between valve stem and rocker arm. Use the
0.04mm and 0.10mm feeler gauges to check
clearances.
(See Fig.1.)
3.
Fig.1
0.04mm Feeler Gauge
Rocker Arm
Valve
18

Re-tighten locknut while holding adjusting
screw stationary. (Fig.5.)
4.
Hold at the screw head.
Fig.5 Tighten Locknut.
Remove 0.04mm feeler, rotate the
crankshaft through two revolutions and
recheck gap.
5.
If clearance is correct, slacken locknut on
the other rocker-arm and repeat steps 1 to 5
above. Finally, replace rocker box cover.
6.
Remember:
Excessive valve clearance will cause loss of
power, due to valve (s) not opening
sufficiently.On theotherhand, a totalloss of
clearance may cause difficult starting due to
valves not closing properly, resulting in loss
of compression.
2.
3.
Turn adjusting-screw approx. 1/2 turn counter-
clockwise to open gap, using appropriate tool -
i.e. Allen hex key. (Fig.3.)
Fig.3
Fig.4
Adjusting Screw Turn approx.
1/2 turn.
Allen Key
Insert 0.1mm feeler gauge between valve
stemandrocker-armand gentlyturnadjusting
screw clockwise until it stops.(Fig.4.)
0.1mm Feeler Gauge
Turn with fingers
until it stops.
19