OS FS-48 Surpass
 Throttle-stop screw ;
Fuel inlet
Throttle lever
Start the engine.
Adjust the needie-vaive,
[ Close the throttle gradually. | Air-bleed screw
Set the throttle at lowest possibie r.p.m.
position, without stopping the engine.
| Find the idling position. |
В 15% (7
Revolutions increase, | The engine runs unevenly or stops.
Stop the engine.
Nose up the model
Hold the model. Sin ар (approx. 15°)
Nose down the mode!
approx. 7
Note: Stop engine by 15° > 7
pinching fuel delivery
tube. Do not touch
needle-valve. Engine runs steadily. ~~ —
4—————————— These adjustmenis can Stop the engine.
be made without stopp- |
ing the engine.
| However, it is advisable
|| Open the Air-bleed| for beginners to stop || Close the Air-bleed
y screw. the engine for safety Ty screw.
| | reasons.
Repeat the procedure while opening and closing
the throttle until the best result is obtained.
Half turn at a
Half turn
L 7 - J
Attention: Do not leave the glowplug connected to the battery while adjusting
the carburettor throttle.
Three key points
For quick, reliable starting, the following three conditions are required:
(D) Good compression. (2) Adequate “glow” at glowplug. (3 Correct mixture.
If the engine fails to start, or does not keep running after being started, check symptoms
against the following chart and take necessary correctiva action. Note: The most common
causes of trouble are marked with three asterisks, the less common problems with one or
two asterisks.
xXx * Insufficient battery. . . .Recharge lead-acid cell or replace dry battery.
; ; capacity (Note: An unused, or almost unused, dry
battery may sometimes be of insufficient
. ® mn . gra +2 as re
2 capacity ¡fit is “old stock")
— + — Glowplug element is . . .Replace glowplug. Check that applied voltage is
burned out. not too high.
L_x-— Something wrong with . .Check glowplug heating using other leads.
battery leads.
"**- Engine “flooded” due . Disconnect battery from glowplug and flip the
® to excessive priming. propeller several times to eject excess fuel.
E (Priming is not necessary at this time.)
Lax* Insufficient priming. . . Repeat priming procedure referring to O
Engine fires 2-—**-Incorrect heating of. .. Voltage too high or too low. Re-check and re-
intermittently but glowplug adjust referring to "BEFORE STARTING
does not run. paragraph 4.
—($)—*x*- Over priming. . . . . .. Disconnect battery from glowplug and flip the
propeller several times to eject excess fuel.
{Priming is not necessary at this time.)
4 . . . .
A)—*—Flipping is not quick .
Practice flipping prop more vigorously.
enough. (When starting the engine by flipping the prop
Engine fires once @—+*-Insufficient battery . . . - Recharge lead-acid cell or replace dry battery.
or twice. then capacity. (Note: An unused, or almost unused, dry
fails to fire. battery may sometimes be of insufficient
La capacity ¡ft is “old stock”)
(3)—%% ~ Insufficient priming. . . . Repeat priming procedure referring to €
Engine starts but —(@ xx * = Mixture too rich. . . . . Close needle-valve half turn (180°) and wait for
revolutions decrease several minutes then re-start. (Priming is not
and engine eventually necessary.)
Engine starts. —{8)—*— Fuel not reaching . . . . . Make sure that tank is filled with fuel. Check
then revolutions the engine. that there is not something wrong with fuel
increase and tubing {kinked or split). Check that carburettor
engine cuts out. is not clogged with dirt.
Engine stops when (3)— x * = Mixture too rich. . . . . . Close the needle-valve a little.
battery leads are (@—* — Mismatch of glow. . . . . Change fuel or glowplug.
disconnected after plug and fuel.
Reversed rotation of a mode! engine may be caused in a number of ways. If the
engine persists in running in the reverse direction after several re-starts, change
starting direction to opposite rotation, or reduce the priming quantity. Too high
a voltage at the glowplug may also cause reversed running. Remove glowplug and
check that element glows bright red, not bright orange/yellow.
The engine starts
but the prop rotates
in the reverse
Valve clearances are correctly set before your engine leaves the factory and, in normal use,
will seldom require adjustment. However, if, after a considerable amount of running time has
accumulated, a loss of power is detected, or if the engine has to be disassembled or repaired
as a result of a crash, valve clearances should be checked and readjusted if necessary. For
checking and adjusting the valve clearances, a valve adjusting kit is available containing two
feeler gauges and two wrenches.
Note: Valve clearances on this engine must be checked and re-set only when the engine is
1) Remove the rocker cover by unscrewing two Allen screws from the rocker box on top of
the cylinder head.
2) Turn propeller until compression is felt, then turn it one quarter turn and stop. Both
valves should now be closed.
3) The required valve clearance is between 0.04 -mm and 0.10 mm (.0015 to .004 in)
measured between the valve stem and rocker-arm. Use the 0.04 mm (thinner one) and
0.10 mm (thicker one) feeler gauges to check clearance. The 0.04 mm feeler should pass
through the gap: the 0.10 mm gauge should not.
4) If the gap is found to be less than 0.04 mm or more than 0.10 mm, carefully slacken the
locknut on the rocker-arm with the 5 mm spanner, turn adjusting screw to open or close
gap, then retighten locknut. Finally, re-check gap and readjust if necessary.
Incorrect valve clearances may cause difficult starting (due to valve not closing properly) or
loss of power {due to valve not opening sufficiently).
The FS-40 SURPASS and FS-48 SURPASS are supplied with silencer as standard, while the
FS-20 and FS-61 are not. For these engines, a silencer is available as an optional part.
Installation for FS-20
Slide the silencer over the exhaust pipe, and secure it with two set-screws supplied with the
silencer. Re-check tightness of screws when engine is hot.
Installation for FS-40 SURPASS, FS-48 SURPASS & FS-61
Screw the exhaust header pipe into the exhaust port until it “bottoms”', then unscrew it just
sufficiently to achieve the required exhaust outlet angle.
Secure the pipe in this position by tightening the locknut firmly against the cylinder head
with the wrench supplied. Then, screw the silencer onto the end of the header pipe and
tighten locknut firmly. Re-check tightness of locknuts when engine is hot.
To ensure that you obtain long life and peak performance from your engine, observe the
1. Avoid running the engine under dusty conditions. If necessary, lay a sheet of plywood or
hardboard in front and under the nose of the môdel when starting the engine.
Foreign matter in the fuel can cause the carburettor jet to be partially clogged. Therefore:
rinse out the fuel tank with methanol or fuel before installing it
fit a fuel filter in the fuel delivery tube between tank and carburettor
fit a fuel filter to the outlet of your squeeze bottle, or to the pump inlet if you use a
manual or electric pump
do not leave your fuel container open needlessly
check filters periodically and clean them when hecessary.
. Do not leave raw fuel in the engine at the conclusion of a flying session: it may cause
corrosion. The best practice is to disconnect the delivery tube from the carburettor while
the engine is running. After the engine has run dry, inject preserving oil or light machine
oil liberally into the crankcase, via the breather hole, to protect the working parts from
corrosion. Remaining fuel in the tank should also be drained off.
4. Clean the exterior of the engine with a clean cotton cloth. If this is not done, oil and dirt
will burn onto the outside of the engine each time it is run and the engine will soon
become blackened.
5. If the engine is not in use for a while (more than two months) remove the glowplug and
rinse out the interior with kerosene (not gasoline), by rotating the crankshaft. Shake out
residue, then inject light machine-oil through the exhaust pipe and breather hole, again
rotating the shaft to distribute the protective oil to all working parts.
6. Avoid unnecessary dismantling of your engine.
® 0 8 N
0.5. ENGINES мев со то.
6-15 3-chome Imagawa Higashisumiyoshi-ku
Osaka 546, Japan. TEL. Osaka (06) 702-0225
© Copyright 1987 by 0.S. Engines Mfg. Co., Ltd. Al rights reserved. Printed in Japan
(FS-20, FS-40surprass, FS-48 surpass & FS-61)
IMPORTANT: Before attempting to operate your engine, please read through
these instructions so as to familiarize yourself with the controls and other
features of the engine. Also, pay careful attention to the recommendations
contained in the ‘Safety Instructions and Warnings" leaflet enclosed.
The FS Series engines are up-to-date overhead-valve four-stroke-cycle engines
for model aircraft use and are the outcome of a long period of technical
— development. The FS Series engines are produced by the world's oldest and
largest model engine manufacturing company; a company which also pioneered
the quantity production of model four-cycle motors.
Like all O.S. engines, the FS Series engines are manufactured to standards of
skilled craftsmanship that have been developed through 50 years of O.S. engine
production history. Fully computerized modern precision machinery and
selected top quality materials are employed to ensure consistent-performance.
and long life.
Note: The engine shown in these instructions is the FS-20.
Installation in the model
A typical method of beam mounting is shown below, left.
0O.S. radial motor mount
(Available as an optional
extra part. See parts list)
Rigid hardwood
(e.g. maple)
> At least 15mm (19/32)
for FS-40 SURPASS,
At least 12mm? к
for FS-20 (1/2)
Make sure that the mounting beams are parallel and that their top surfaces are in the same
De a
| T f Ш
; . . i op surfaces are not , |
Front view Side view ' in the same plane, Opposite beam
+ Top surfaces are not
Top surfaces are in the same plane. in the same plane.
Re-align the surfaces
Engine does not rest firmly.
as necessary
How to fasten the mounting screws.
Tighten second nut firmly
| down onto first nut.
3mm steel nut for FS-20 Tighten this nut first.
3.6mm steel nut. i
for FS-40 SURPASS, Spring washer or
FS-48 SURPASS & os lock washer
3mm steel Allen screw
for FS-20
3.5mm steel Allen screw
for FS-40 SURPASS,
Spring washer
0.8. radial motor mount
© @ cam)
Un a
3mm steel screw
for FS-20
3.5mm steel screw
for FS-40 SURPASS,
Wooden mount FS- a8 SURPASS &
Bench mount
Usually, the engine is installed directly in the model. ¡f, however, you are unfamiliar with
handling model engines, it is recommended that you first run the engine on a bench mount
as shown below.
> You may make such a bench mount as
A Fix engine with sketched below.
TN clamps provided.
Install the engine with screws and nuts,
referring to "How to fasten mounting
Approx. 150mm to 250mm
(6" to 10"") according to
. the engine size
At least 12mm (1/2) | Co Rigid
for FS-20
At least 15mm (19/32”)
Commercially available bench
Refer to mounting hole pattern enclosed.
Wooden case, etc.
(Stake firmiy to ground
or clamp to bench-top.)
“fm 1.5mm
Choke rod Allen key
The FS Series engines are equipped with The choke rod
is released and
self-reopening choke valves. In the case
of the FS-20, FS-40 Surpass and FS-48 © pd ke valve
Surpass, cut the choke rod (supplied)
to the length indicated, then secure the
rod by tightening the set screw, using
1.6mm Allen wrench (supplied), after
installing the engine.
Frame sides
of fuselage
approx. 7mm | approx. y
. 2mm Е
Choke rod
The needle-valve supplied with this-engine is designed to incorporate an extension so that,
when the engine is enclosed within the fuselage, the needle-valve may be adjusted from the
outside. Cut the L-shaped rod supplied to the required length, insert it into needle's centre
hole and secure it by tightening the set-screw in the needle-valve knob with 1.6mm. Allen
key supplied.
In the following instructions, engine parts are identified as shown:
Glow plug Rocker cover
Carburettor Exhaust pipe
Fuel inlet
Propeller washer
AT Crankshaft
Choke valve
Propeller nut
Drive washer
Breather Nipple
pp Needle-valve
Tools, accessories, etc.
The following items are necessary for operating the engine.
1 Fuel
Model glowplug engine fuel of good quality, preferably containing a small percentage
of nitromethane. (See "Advice on selection of fuel and propeller’)
2 Glowplug
An O.S. Type “F” glowplug (recommended) is fitted to the engine.
3 Propeller
Suggested propellers are shown in the separate instructions sheet.
4 Glowplug battery
The power source for heating the glowplug may be either a large
heavy-duty 1.5-volt dry cell, or preferably, a 2-volt rechargeable
lead-acid cell (accumulator).
Resistance coil
{nichrome wire)
If a 2-volt cell is employed, use
a resistance wire, as shown, to
reduce applied voitage, otherwise
element will overheat and burn
9e ess
7 owes vol ope
ve самое ©
or 2 voit rechargeable
lead-acid cell (at least 5Ah)
1.5 volt heavy-duty
dry battery
Adjust applied voltage by changing the position of clip
on resistance coil until glowplug element is glowing
bright red or orange colour.
5 Plug wrench
Used for tightening glowplug. The O.S. two-way socket For tightening
wrench, which also fits the propeller-nut, is available as an glowplug DA
optional accessory.
Also, the O.S. long socket wrench w/plug grip is very conveni-
ent for use when the engine is hidden in cowl.
6 Battery leads Lor tightening
propeller nut
These are used to conduct current from the battery to the
glowplug. Basically, two leads, with clips, as illustrated above,
are required, but, for greater convenience, twin leads with
special glowplug connectors, as shown on the right, are com-
mercially available.
7 Fuel tank
Suggested tank size is shown in the separate instruction sheet.
For bench running, a rectangular tank of a little larger capacity
may be found more convenient.
8 Fuel bottle or pump
For filling the fuel tank, a simple, polyethylene “squeeze”
bottle, with a suitable spout, is all that is required. Alternative- /
ly, one of the purpose-made manual or electric fuel pumps ;
may be used to transfer fuel directly from your fuel container 3
to the fuel tank.
9 Silicone tubing
This is required for the piping between the fuel tank and engine.
10 Safety (“Chicken”) stick
This is used to flip the propeller -for starting and so protect
one's fingers against possible injury. An alternative is a thick
ribbed rubber finger protector.
Fuel pumps
Fuel bulb
Safety stick
11 Electric starter and starter battery
An electric starter may be used to start the engine. However,
this, together with the 12-volt battery required for it, is a
rather costly luxury. Most engines can be started more quickly
with an electric starter, but, with practice, even beginners will
find FS Series engines quite easy to start by hand.
Fuel and pressure lines
Connect suitable lengths of silicone tubing, as illustrated, after installing the engine.
Piping and position of fuel tank
Attention to tank height
; Fuel level
Note: When cutting silicone tubing.....
Silicone tubing
Do not use wire
Use knife or razor blade. cutters or pliers.
1 15—10m
Locate the fuel tank so the top of the tank is
5 — 1Omm (1/4—3/8"") above the level of the
* |f you should need to clean out silicone
tubes, use methanol or glow-fuel, not
gasoline nor kerosene,
€ Fitting the glowplug @ Fitting the propeller
Tighten firmly with the thumb,
First, fit the propeller to the engine by tighten-
forefinger and middle finger as
ing the prop. nut lightly, and make sure of the
illustrated. position where compression is felt, turning the
propeller counter-clockwise slowly. Then
Glowplug tighten firmly as explained below.
wrench (0.5. With a four stroke engine, the compression is
two-way felt with every two revolutions.
socket ;
wrench) Socket wren:h
(0.8. two-way
socket wrench
Tighten the
propeller nut
firmly so that
compression is
Washer x
first felt
Glow plug around this
(Carefully position (ie.
screw-in with blades
with fingers horizontal)
with wrench.)
when turning
— the propeller
— in the direc-
tion of arrow.
O Checking for gas leakage @ Filling the fuel tank
Check gas leakage by 7 Re-connect delivery
turning the opel) tube to engine after
up to this position >, tank is filled.
after compression |< ==
Dribble a few drops
MT of fuel around the
= 723) _-9lowplug.
Breather pipe (to
the outside of
the fuselage)
e Disconnect
‚ delivery tube
The compression is trom the fuel
first felt around this inlet, and
Y position when turning connect it to
— {| lowly. the tubing
— the propeller slowly from the fuel
| (model glow-
, > | plug engine fuel)
If leakage is detected, remove the glow-
plug, carefully wipe threads, re-insert and
‘tighten firmly.
Do not let dirt or
Fuel pump dust enter fuel can.
© Setting the needle-valve O Opening and closing of the needle-valve
TT Turn the needle-valve in
\ the direction of arrow
_ slowly, without forcing,
until it stops.
Г я Needie-valve
yd Set-screw
The position where the needle-valve
stops is the fully closed position. It may
be convenient to remember the position
of the set-screw at this time.
Turn the needle-valve in
the direction of arrow
a from the closed position.
Turn needle-valve clockwise to close (for
leaner mixture).
Turn needie-valve counter-clockwise to
open {for richer mixture).
(Regarding number of
turns, refer to the separate
instructions sheet.)
@ Open the throttle fully © Priming
Fully opened
Fuel will flow from tank to carburettor as
propeller is turned.
Fully closed
w Close the
air intake
by operating
the choke
Turn the propeller four revolutions,
then RELEASE choke.
Priming quantity
If very strong compression is felt
when trying to turn the propeller
counterclockwise, too much fuel
has been drawn into the engine. In
this case, do not use force but turn
the propeller clockwise slowly to
eject excess fuel through exhaust
Turn the propeller two or three
revolutions in the direction of
arrow while keeping the choke
open, and stop it at the position
where the compression is first
felt. (With correct priming, a
slight spray of fuel may be
emitted through the exhaust
{0 Heat glowplug
| Connect battery leads as shown (Polarity
is immaterial.)
battery |
о (ес! to the glow-
plug and the other
to any convenient
part of the engine,
or use special con-
nector as shown.
Glowplug battery,
Place as far to the
rear as possible.
Battery leads
afety stick
Assistant should hold
the model so that it
cannot move forward
when the engine starts.
Note for those starting a model engine for the first time.
® Flip propeller to start
Set the throttie at the
half opened pasition.
Flip the propeller vigorously in
the REVERSE direction from
the centre of the right blade,
using a safety stick.
Note for those starting a model four-stroke engine for
the first time. (To be read in conjunction with steps @
and €
Your engine may also be started by flipping the propeller
counter-clockwise (i.e. in the normal running direction).
However, the bounced start method, as described in
steps Y and (Bis considered a safer and more reliable
procedure for the beginner. With a four-stroke engine,
especially if it is over-primed, flipping the prop in the
running direction can result in a sharp “kick” as the
engine fires. ;
When it is intended to start the engine, as recommended,
by flipping the prop in the reverse direction, be sure to
position the propeller blade so that the beginning of the
compression-stroke is felt as the prop is turned in the
normal (counter-clockwise) running direction, as noted
in steps @ and © . This ensures that the propeller is
free to rotate a full 1% turns before being bounced back
cleanly in the running direction. Any attempt to flip
the prop clockwise, from the position where compres-
sion is first felt while turning the prop CLOCKWISE, is
likely to be met by strong resistance and pre-ignition.
® Engine starts
® Needie-valve adjustment (1)
The engine will then bounce smartly in the
counter-clockwise direction to the point
where ignition and expansion of the
charge takes: place.
If the engine does not start after more
than five flips, repeat procedure Qto @-.
If the engine still does not start after re-
peating the procedure two or three times,
refer to the "TROUBLE SHOOTING”
chart later in this instruction leaflet.
the rotating
—T propeller.
Close the needle-valve gradually until
exhaust gas color changes from white to
(P Disconnect battery leads
(P Needle-valve adjustment (2)
Disconnect the battery
leads from the engine
with care so that the plug
clip does not touch the —
rotating propeller. SS’
| >
| - ©
\ Во > the engine stops
\ ENDE when battery leads
\ wa A are disconnected,
CL © close the needle-
\ a valve a little (approx.
\, % 80) further, and
5, Ts
restart the engine.
As the needle-valve is closed gradually, the
revolutions of the engine will be increased
and the grey exhaust smoke will become
less dense.
Key to the needie-valve
0 (Turn 10 — 15° at a time.)
Turn the needie-valve 10 — 15° in the direc-
tion of arrow, and wait for the change of
r.p.m. After the revolutions of the engine
are increased, turn the needle-valve another
10 — 15° and wait for the next change of
As the speed of the engine does not instant-
ly change with needle-valve readjustment,
small movements, with pauses between, are
necessary to arrive at the optimum setting.
@ Needle-valve adjustment — Summary
| Practical best (optimum) needle-valve setting. |
| Maximum rpm setting (“Lean”). |
“Rich” needie-valve setting
when starting the engine.
NOTE: This sketch is for reference purposes only.
Actual needie positions may differ from those shown.
On starting from cold, with the needle-valve set at the rich starting position:
| a good deal of white smoke is emitted. |
| As needie-valve is closed and revolutions are increased:
| exhaust smoke will be less dense and grey in colour. |
| Further needie-valve closure:
| revolutions will increase and exhaust smoke will be reduced. |
| Finally:
maximum rpm are reached and will fall off (or engine will stop) if needle-valve is closed
“any further. Exhaust gas will be very light. ; ВЕ UU em те sense
| Now, re-open needle-valve 20°-30°
This will produce the practical best (i.e. optimum) rpm setting (200-300 rpm lower than
maximum rpm). A light grey exhaust emission may be observed.
Take note of this position of the needie-valve.
@ How to stop the engine
Close the throttle to reduce to the lowest
possible r.p.m.
Pinch the fuel tube with fingers or
_disconnect it from the fuel inlet.
Do not touch the engine as it is very hot!
Starting the engine with an electric starter
If an electric starter is used, the procedures are the same as for hand starting outlined above,
except for steps @ and @ which are modified as follows:
@ Fit an O.S. solid alloy spinner-nut to the engine (available as an optional extra part) for
centering the rubber drive insert of the starter. Alternatively, a spinner assembly, enclosing
the propeller boss, may be used, but make sure that it is of sturdy construction and that the
spinner shell does not loosen when the starter is used.
Warning: When using a spinner assembly, make sure EEE DEA
that the notches in the spinner shell are large enough to Fully closed Fully opened
clear the propeller blades and so do not cut into and position 15, % position
weaken the blade roots. NM
® Reset the throttle at one-third open from the | = И
fully closed position. Bring the starter into contact
with the spinner-nut or spinner and depress the starter
‘switch for one or two seconds. Repeat if necessary.
When the engine fires, withdraw the starter imm-
Attention: Never close the choke valve when applying
the starter. Such an action will cause an excess quanti-
ty of fuel to be drawn into the cylinder and result in an
hydraulic lock that may damage the engine.
“Set at this position.
Subsequent starting procedure
Once the optimum needle-valve setting has been established" (see O “Needle-valve adjust-
ment — Summary") the procedure for starting is simplified as follows:
1) Open the needle-valve one half-turn (180°) from the optimum setting.
2) When the engine is cold, prime the engine by rotating the propeller two revolutions with
the choke closed. When it is warm, after a run, first try just flipping the propeller with the
throttle in the idling position after re-energising the glowplug. If the engine does not re-
start, re-prime it by closing the choke valve while rotating the propeller twice with the
throttle open. Initially, high temperature inside the combustion chamber may turn the
liquid fuel into gas and emit it through the exhaust pipe. Therefore, repeat the priming
procedure once or twice until the cylinder becomes cool enough for restarting.
Set the throttle one-third open from the fully closed position, energize the glowplug and
flip the prop. When the engine starts, re-open the throttle and re-adjust the needle-valve
to the optimum setting.
Note: When re-starting the engine on the same day, provided that atmospheric condi-
tions have not changed significantly, it may be pracicable to re-start the engine
on its optimum (running) needle-valve setting. Also, if the engine is being re-
started immediately after a run (i.e. hot), priming should not be necessary.
All internal-combustion engines benefit, to some degree, from extra care when they are run
for the first few times — known as running-in or breaking-in. This is because the working
parts of a new engine take a little time to settle down after being subjected to high tempera-
tures and stresses. However, because O.S. engines are made with the aid of the finest
modern precision machinery and from the best and most suitable materials, only a very short
and simple running-in procedure is required and can be carried out with the engine installed
in the model. The process is as follows:
1) Start the engine and, with the throttle fully open, open the needle-valve an extra half
turn (180°) from the optimum setting. This will produce a rich mixture-that will result in
cooler running. Allow the engine to run out a full tank on the ground. (Avoid dusty sur-
2) Now fly the model with the needle-valve re-set 20—30 degrees open from the optimum
setting (i.e. 40°—60° from the highest rpm setting).
3) Close the needle-valve very slightly on successive flights so that the engine is running on
its optimum needle setting at the fifth or sixth flight.
Use a good quality commercial fuel containing 5 — 15% nitromethane or one of the blends
shown in the table. Fuel “A” is suitable for running-in and ordinary use. Fuel “B” is for use
when more power is required and for improved flexibility. Note that even a small guantity
of nitromethane (3 — 5%) will improve flexibility, making the needle-valve adjustment less
critical and improving throttle response. Use only materials of the highest purity. Synthetic
oils are permissible but are less tolerant of a “lean run” than castor-oil. If, therefore, a
synthetic lubricant is used in the fuel, readjust the needle-valve to a slightly richer setting, as
a safety measure, in case the fuel/air mixture becomes too lean through manoeuvres in flight.
If a more powerful fuel is used, the engine should be checked out to make sure that it is suf-
ficiently run-in to operate on that particular fuel without overheating. Do not use fuels
containing less than 20% lubricant.
Attention: Methanol (methyl alcohol) and
nitromethane are poisonous. Keep A B
out the reach of small children. Use Methanol 75% | 70%
and keep in a well ventilated area, Castor Oil 20% | 20%
also keep away from heat and open Nitromethane 5% 10%
Suggested propellers are shown -in the separate instruction sheet. As the ideal propeller
diameter, pitch and blade area vary according to the size, weight and type of model, final
propeller selection can be made after practical experiment.
Warning: Check the balance of the propeller before fitting it to the engine. Unbalanced
propellers cause vibration and loss of power. There is always a danger, especially
with nylon propellers (and depending on engine speed and weather conditons), of
the propeller fracturing and a blade flying off and, obviously, this can cause
injury. Therefore, never crouch over the engine when it is running and keep all
onlookers well back — preferably behind the model. If a spinner is used, make
sure that the spinner notches are large enough to clear the propeller blades and so
do not cut into and weaken the blade roots.
The FS Series engines are equipped with a throttle type carburettor which provides a wide
range of engine speed control. With the throttle lever linked to a suitable electric servo in
the model, movement of the throttle control on the transmitter will enable engine revolu-
tions to be varied, proportionally, from idling speed to full power.
The carburettor of your engine has been factory set for the approximate best results and
no adjustment (except to the needle-valve) should be required provided that the fuel tank
is correctly located, as previously described. After the engine has been run-in, check the
operation of the throttle according to the following chart. Re-adjust the controls only when
Start the engine. |
Make sure that the throttle is
fully open.
| Adjust the needle-valve. | 20-30 open from maximum r.p.m.
| Close the throttle gradually. |
- - 4 — The position where the lowest
| Find the idling position. | possible r.p.m., with steady running,
1 is obtained.
Set the throttle opening by means
of the throttle trim on the transmitter
or by adjusting the throttle-stop screw
so that the lowest practical speed,
without risk of the engine stopping,
is obtained.
| Fix the idling position. |
Re-set the idling position at
a little higher r.p.m.
Make sure that the engine runs at
| Open the Heels fully. high speed.
Does the engine run
at high speed?
Engine stops.
| +— — — — Yes.
Continue running at high speed
for 10 seconds.
| Close the throttle abyuptly. |
| Run at idling speed for 5 seconds. |
—— Engine stops.
Does the engine stop?
| «——————— No.
Abruptly apply full throttle.
Does the engine run
at high speed?
Г Engine stops. —
Refer to the CARBURETTOR
section on next page.
O.S. FS-48 14-77 4917I>> MMS
sE57onf-. @MEE/XT INI TY
{LH à [OS 457 LI->- FSA NIE
по Hk kas, BRL RE) CHR RITE)
УХО аля ВВ СС < 7 о
№ (К 0 7 4 7
(Ю — < 0 + С 7н Я т & НВ)
& U 7% 7H HAE 7 À)
RETIRE 4 7D 27 — UE
— RDA 7H. MEE >
НИ & AE L722E— №
М В оп ^^ оз
12X6, 12.5X6
11 X6, 11X7, 11X7.5
12X5, 12X6
10 х 8, 10х9, 10.5х 8
10.5 х 9, 11X86, 11X7
ВАНЯ 7 7
#7200ссО ТН > 7 EMEIL TE Eo AI29-0 MAT DEN
{7 12 4 1
7.89cc (0.481 cu.in.)
Detailed information on the operation and care of O.S. FS
Series engines will be found in the enclosed large fully-
illustrated 4-page sheet entitled “INSTRUCTIONS FOR
This smaller sheet is supplementary to the full instructions
and is to advise you of the recommended propeller sizes,
fuel tank size and needle-valve setting for the FS-48 Surpass
mode! only, together with specifications and part numbers.
IMPORTANT: Before attempting to operate your FS-48,
please read through both instruction sheets and also pay
careful attention to the “Safety Instructions and Warnings”
leaflet also enclosed. |
The FS-48 Surpass is one of a new generation of O.S. four-
stroke engines that benefits from our unrivalled experience
in model four-stroke engine design and production, which
began with the O.S. FS-60, the engine that brought the
advantages of the four-stroke-cycle to the notice of the
model world and began the model four-stroke revolution.
The choice of propeller depends on the size and weight of
the model and on the type of flying envisaged. Determine
the best size after practical experiment. As starting points,
suggested propellers are listed below.
A 7 | Bore 23.0mm (0.906 in.)
А К — 7 Stroke 19.0mm (0.748in.)
E AB [a Ex XX | Practical R.P.M. 2,200-12,000r.p.m.
HE # | Power output 0.8BHP/12,000r.p.m.
E & | Weight
(#4 12 $—f$) | (including silencer) 4129 (14.50.2.)
For scale models of aircraft with
large wing area and low wing loading 12 хбог 12.5 х 6
11 х 6, 11 х 7, 11 х 7.5,
12 х бог 12 хб
For light-aircraft type models
(sport, scale or trainer)
10 x 8, 10 x 9, 105. x 8,
For sport type aerobatic models 10.5 x 9. 11 x 6 or 11 x 7
For running-in purposes, an 11 x 7 propeller will be suitable.
A fuel tank of 200cc (6.8 oz.) capacity will run this engine
for approximately 12 minutes.
Turn the needle-valve 2 to 3 turns counter-clockwise from
the fully closed position.
mas No. a Z Description ma N > # Description
45581000 | 77-77—A Crankcase 45860000 | T-7— 7 LT —E Intake Valve Assembly
45801100 | 75 А + 7) /\ — Cam Cover 45260010 | TXJ—Ah-/417 —£ Exhaust Valve Assembly
45802000 | V5» v7 b Crankshaft 45261010 | AyH—7—4h —K Rocker Arm Assembly
45803100 | YJ X— S54 F— Cylinder Liner 45261400 | Oyh—<##—H —À Rocker Support Assembly
45803200 | EZ h> Piston 45262010 | HL v7 bh Camshaft
45803400 | EX bh UT Piston Ring 45664000 | AL 74007 Cam Follower
45804000 | SU 4— Ny RK {NIVTH Cylinder Head (w/Valve Ass’y) 45866000 | 7y7Za1-Avk Push Rod
45804100 | YU 4—. yk Cylinder Head 45866100 | Fv 2 +OvyK-hHh/N— — | Push Rod Cover Assembly
45204210 | Ну 7) — + р /\— Rocker Cover 45869000 | y 7—7 > VIA—)VF — | Intake Pipe Assembly
45205000 | я аук Connecting Rod 22681953 | FJ HF.-y TI (7741) Breather Nipple (w/Washer)
45806000 | EX KE Piston Pin 71615009 | 70—-737(347F) Glow Plug Type “F”
45807000 | H/X—-TL—Fh Cover Plate 45881000 | Xv7L4A—-Zay bh Carburettor Complete
45808000 | E7417:-7y74 (4-1) Drive Washer (w/Key) 45825010 | +7 НН — ЖЖ Silencer
23209003 | ONS Tv Ty Propeller Washer 45226000 | Ix —Ab vik — X | Exhaust Header Pipe Assembly
23210007 | 7a~xZ «Fv hb Propeller Nut 45884000 | Fa—-7-/117 —EK Choke Valve Assembly
45813000 | AV Va—-tvb Screw Set * 72200060 | 4-7 HAB | Valve Adjusting Kit
45814100 | Ny RK HRA vb Head Gasket 71913000 | SV FH by В Radial Motor Mount
26531005 | 495319447 KAT). G() | Crankshaft Ball Bearing (Front) * 45262091 | 7) БУ м 7 Reverse-rotation Camshaft
27330000 | 7597747 bh-N7 77 (6) | Crankshaft Ball Bearing (Rear) * 23024008 | ZE -FH—:+7h Spinner Nut
45231100 | ША Ма XTYLT Camshaft Ball Bearing
* El + 32 Optional extra
О. 5. ту у
Mis (06) 702-022 586 (48)
The specifications are subject to alteration for improvement without notice.
0.5. ENGINES mec coro
6-15 3-chome lmagawa Higashisumiyoshi-ku
Osaka 546, Japan.
TEL. Osaka (06) 702-0225
O Copyright 1987 by O.S. Engines Mfg. Co., Ltd.
All rights reserved. Printed in Japan
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