O.S. engine MAX-12TR Series 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.
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CONTENTS
SAFETY INSTRUCTIONS AND
WARNINGS ABOUT YOUR O.S. ENGINE
INTRODUCTION, BASIC ENGINE PARTS
INSTALLATION
AIR CLEANER TYPE 103
GLOWPLUG
TOOLS, ACCESSORIES, etc.
CARBURETTOR CONTROLS
PRESSURIZED FUEL SYSTEM
STARTING THE ENGINE &
RUNNING-IN('Breaking-in)
FINALADJUSTMENT
CARBURETTOR CLEANLINESS
CARE AND MAINTENANCE
O.S. GENUINE PARTS &
ACCESSORIES
ENGINES EXPLODED VIEW &
PARTS LIST
CARBURETTOR EXPLODED VIEW &
PARTS LIST
THREE VIEW DRAWING
MEMO
IF THE ENGINE FAILS TO START
2 ~ 5
7
~ 8
10
~ 11
11
~ 12
13
~ 14
12
8
9
6
15
17
18
19
28
15
~ 16
20
~ 23
24
~ 25
26
~ 27
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 poi-
sonous. 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 en-
closed 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 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 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.
•
5

INSTALLING THE GLOWPLUG
Carburettor
Install washer on glowplug
and insert carefully into
cylinder-head, making sure
that it is not cross-threaded
before tightening firmly.
BASIC ENGINE PARTS
The MAX-12TR is high-perfomance
engines for 1/10 class R/C racing cars.
There are two verions, the one with 10M
carburettor and the other with 10J
carburettor. The MAX-12TR has a
conventional crankshaft, while the MAX-
12TR(P) employs a special crankshaft
with integral pilot shaft.
Crankshaft
Glow plug
Washer
Drive Hub
Crankcase
Beam Mount
Heatsink Head
Cover Plate
As delivered, the engine has its carburetor
lightly fit into its intake. Secure it changing
its angle according to the car chassis.
NOTE
NOTE: With this engine, the piston will feel
tight at the top of its stroke when the engine
is cold. This is normal. The piston and
cylinder are designed to achieve a perfect
running clearance when they reach their
normal running temperatures.
Standard accessories
Glow Plug A5 Super Air Cleaner 103 Assembly
103 Cleaner Body
103 Filter Elements (2pcs.)
Exhaust seal ring
Instruction manual
MAX-12TR
Exhaust
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 3mm or 4-40 steel Allen hexagon
socket type.
If existing holes in the engine mount do not align
perfectly with engine mounting lugs, enlarge
them slightly with a needle-file so that screws
enter vertically.
Chassis
Chamfer inside edges of bearers.
INSTALLATION OF THE CARBURETTOR
As delivered, the engine has its carburettor
lightly fit into the intake boss. Secure it as
follows.
Loosen the retainer screw, 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.
Rotate the retainer nut
gently until it stops. Tighten a further 60-90˚
Fit the exhaust seal ring supplied.
7

AIR CLEANER TYPE 103
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. The lower height
of the Super Air-Cleaner 103 also facilitates
easier installation in cars where available
space may be restricted.
Position the air cleaner correctly, so that it does
not foul the cylinder-head or obstruct the needle-
valve.
INSTALLING 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
adheringtotheelement.If
your fingers become
contaminated, wash them
with soap and water.
Duringstorage,theoilmayhavebecomeunevenly
dispersed through the element. This will be
indicated if the blue colour of the element material
appears patchy. In this case, place the element in
asmallplasticbagandgentlyrubitbetweenfinger
and thumb to redistribute the oil.
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
Insert beneath flange
•
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•
8

GLOWPLUG
Since the compatibility of glowplug and fuel may have
a marked effect on performance and reliability, it may
be worthwhile to choose the R/C type plug found
most suitable after tests.Recommended O.S. plugs
are A5, No.8 and R5. Carefully fit plug finger-tight,
before final tightening with the correct size plug
wrench.
Glowplug life
Particularly in the case of very high performance
engines,
glowplugs must be regarded as expendable
items.
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.:
•
•
•
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.
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.
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9

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 AT LEAST 18%
lubricant.Thisengineisdesignedtorunonbothlowand
high nitromethane content fuels,i.e. from mild mixtures
containing a few percent of nitromethane, up to high-
speed racing fuels containing 40%,nitromethane.
Generally, power output is increased
- up to a certain
point - asthenitromethanecontentofthefuelisincreased.
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, 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 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.
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.
Keepitawayfromopenflame,excessiveheat,
sources of sparks, or anything else which
might ignite it.
Reminder!
ELECTRIC STARTER BOX
For starting the engine.
BATTERY INTEGRATED GLOWPLUG HEATER
Commercialy available handy
glowplug heater in which the
glowplug battery and battery
leads are integrated.
FUEL PUMP
For filling the fuel tank, a simple,
polyethylene "squeeze" bottle,
with a suitable spout, is required.
10

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.
CARBURETTOR CONTROLS (10J)
The Needle-Valve:
The Mixture Control Screw:
The Throttle Stop Screw:
For setting the minimum idling speed.
Needle Valve
Mixture Control Valve
Assembly Screw
Throttle Stop Screw
Ball Link
NOTE:
Readjustment may
be necessary, occa-
sionally to allow for
changes in fuel for-
mula, gear ratio or
clutch engagement
point.
Three adjustable controls are provided on this
carburettor.
For adjusting the mixture strength when the throttle
is fully open.
For adjusting the mixture strength at part-
throttle and idling speeds, to obtain steady
idling and smooth acceleration to mid speeds.
11
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•
•

CARBURETTOR CONTROLS (10M)
The Needle-Valve:
The Mixture Control Screw:
The Throttle Stop Screw:
Three adjustable controls are provided on this
carburettor.
For adjusting the mixture strength when the throttle
is fully open.
For adjusting the mixture strength at part-
throttle and idling speeds, to obtain steady
idling and smooth acceleration to mid speeds.
NOTE:
Readjustment may
be necessary, occa-
sionally to allow for
changes in fuel, gear
ratio or clutch en-
gagement point.
Needle Valve
Mixture Control Valve
Assembly Screw
Throttle
Stop Screw
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 installing the air
cleaner. Dust and dirt that may otherwise be drawn
into the engine will rapidly shorten its life.
PRESSURIZED FUEL SYSTEM
•
•
Silencer
Fuel Tank
Silicone tubing
Connect suitable length of
Silicone tubing between fuel
tank and silencer.
For setting the minimum idling speed:
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12

approx 1mm
approx 0.3-0.5mm
The following procedure is suitable for these engines
when the O.S. T-1030 tuned silencer and a fuel
containing up to 30% nitromethane are used.
Use the same fuel as is to be employed for all initial
running and containing NOT LESS THAN 18%
lubricant.
Temporarily remove the glowplug to check that it
glows bright red when energized.
Open the Needle-Valve 2 turns from the fully closed
position.
DO NOT energize glowplug,
but apply electric starter to
draw fuel to carburettor.
Re-check the needle-valve
and throttle settings. Turn
the needle-valve clockwise
slowly and gently until it
stops. This is the fully
closed position.Do not use
force to turn the needle-valve beyond this point.
•
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•
Open
Close
Needle Valve
In case of the 10J caburettor
•
In case of the 10M caburettor
Set the throttle-stop screw so
that the minimum throttle
opening (idle setting) is
approximately 1.0mm.
•
Throttle Stop Screw
•
STARTING THE ENGINE & RUNNING-IN ('Breaking-in')
Set the throttle-stop screw so
that the minimum throttle
opening (idle setting) is
approximately 0.3-0.5mm.
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!
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13

30˚
Whentheenginestarts,firstallowittooperateinshort
runsonitsveryrichstartingsettings,withtheglowplug
batterystillconnectedandwithitsdrivingwheelsclear
of the ground. The rich mixture will, under these
conditions,provideadequate lubricationand cooling,
indicated by profuse smoke from the exhaust.
Next, disconnect the glowplug battery and try
running the car on the track. If the engine stalls,
open the throttle fractionally, but try to keep the
engine running as rich as possible: if it stops
because of being excessively over-rich, close the
Needle-Valve 30˚ and try again.
Runthecaronthetrackuntilfivetanksoffuelhasbeen
consumed, then close the Needle-Valve 30˚. Repeat
this procedure until around 5 times of fuel have been
consumed, during which time the throttle may be
opened for brief bursts of increased power. If the
engine stops at medium speeds, close the Mixture
Screw 45-90˚.
Needle
The position of the needle-valve
when starting the engine.
Close the needle-valve approx.
30˚ after running the vehicle for
every five full tanks of fuel.
Repeat this procedure around 5
times.
•
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•
30˚
30˚
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.
•
If the engine should need to be disassembled (e.g. for
cleaning or minor parts replacement) it is advisable to
return the Needle-Valve to the original rich, starting
setting and check whether further running-in time is
required before the car is raced again. In the event of
any major working parts(e,g, piston/cylinder liner
assembly) being replaced, the complete running-in
should be repeated.
Remember!
14

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. At this time cover
the plug hole with waste so that splashing fuel will
not get into your eyes or mouth.
•
•
•
Run the vehicle (with throttle fully open) over the
longest available straight course, in order to observe
the model's speed. Next return the car to the starting
point, close the Needle-Valve 30˚ and repeat the
run, taking note of the improvement in performance.
Continue with further runs, gradually reducing the
Needle-Valve setting and aiming to achieve the
highest straight-line speed. Remember, however,
that, if the Needle-Valve is shut down too far, the
engine will overheat and, accompanied by visibly
diminished exhaust smoke, the model will lose
speed. At this point, throttle down immediately, stop
the vehicle and reopen the Needle-Valve 30˚.
With the engine running, close the throttle and allow
it to idle for about five seconds, then reopen the
throttle fully. If, at this point, the engine puffs out an
excessive amount of smoke and the vehicle does
not accelerate smoothly and rapidly, it is probable
that the idling mixture is too rich.
FINAL ADJUSTMENT
•
•
•
Having established the optimum Needle-Valve
setting, check the Mixture Control Valve setting as
follows.
15

In this case, turn the Mixture Control Valve
clockwise 45˚. If, on the other hand, the engine
tends to speed up momentarily and then cut out
abruptly when the throttle is opened,the idling
mixture is too lean. Correct this by turning the
Mixture Control Valve counter-clockwise 45˚.
Warning!
Carry out adjustments patiently, under actual
running conditions, until the engine responds
quickly and positively to the throttle control.
Mixture adjustments (whether via the Mixture
Control Valve, or the Needle-Valve) cannot be
made accurately under 'no-load' conditions,
which, in any case, are not advised, since such
operation carries the risk of seriously damaging
the engine through over-revving and overheating.
•
•
With the optimum mixture control position, light
smoke is visible during high speed running,and the
engine revolutions increase smoothly during
acceleration. Remember that, if the engine is
operated with the fuel/air mixture slightly too lean, it
will overheat and run unevenly. As with all engines,
it is advisable to set both needle-valve and mixture
control screw very slightly on the rich side of the best
rpm setting, as a safety measure.
If the engine runs too fast with the throttle closed,
the throttle stop screw should be turned counter-
clockwise to allow the throttle opening to be
reduced.
•
•
•
Finally, beyond the nominal break-in period, a slight
readjustment toward a leaner needle setting may be
required to maintain performance.
16

BALL LINK AND SLIDE VALVE EXTENSION
It is seldom necessary to separate the slide-valve
extension from the slide-valve itself. For cleaning,
withdraw this complete sub-assembly from the
carburettor body after removing the slide-valve guide
screw. Then wash with methanol or glow-fuel.
(Note: take care not to lose the guide screw;it is a
special one.) When it is necessary to adjust the ball-
link position, loosen the ball-link retaining screw with
a 3mm hexagon key, re-align the ball-link and re-
tughten the screw firmly.
(In case of the 10J caburettor)
REALIGNMENT OF MIXTURE CONTROL VALVE
In the course of making carburettor adjustments, it is
just possible that the Mixture Control Valve may be
inadvertently screwed in or out too far and thereby
moved beyond its effective adjustment range.Its basic
position can be found by first rotating the Mixture
Control Valve until its slotted head is flush with the
carburettor body. The valve is then screwed in exactly
2.5 turn to re-establish its neutral position.
Mixture Control Valve
Carburettor Body
First rotate the Mixture Control
Valve until its slotted head is
flush with the carburettor body.
Then screw the valve in exactly
2.5 turn.
This is the standard position.
In case of the 10J caburettor
In case of the 10M caburettor
Carburettor Body
Mixture Control Valve
First rotate the Mixture Control
Valve until its slotted head is
flush with the carburettor body.
Then screw the valve in
exactly 0.5 turn.
This is the standard position.
Throttle Lever
CARBURETTOR CLEANLINESS
The correct functioning of the carburettor depends on its small fuel orifices remaining clear.
17
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4.
CARE AND MAINTENANCE
1.
2.
3.
The minute particles of foreign matter, that are
present in any fuel may, by accumulating and
partially obstructing fuel flow, cause engine
performance to become erratic and unreliable.
O.S. 'Super-Filters' (large and small) are available,
as optional extras, to deal with this problem.
One of these filters, fitted to the outlet tube inside
your refueling container, will prevent the entry of
foreign material into the fuel tank. It is also
recommended that a good in-line filter be installed
between the tank and carburetor.
Do not forget to clean the filters regularly to remove
dirt and lint that accumulate on the filter screens.
Also, clean the carburetor itself occasionally.
At the end of each operating session, drain out any
fuel that may remain in the fuel tank.
Afterwards,energize the glow-plug and try to restart
the engine, to burn off any fuel that may remain
inside the engine. Repeat this procedure until the
engine fails to fire. Do this while the engine is still
warm.
Then, inject some after-run oil into the engine, and
rotate the engine with an electric starter for 4 to 5
seconds to distribute the oil to all the working
parts.
Note:
5.
Do not inject after-run oil into the carburetor as
this may cause the O-rings inside the carburetor
to deteriorate. These procedures will reduce the
risks of starting difficulties or corrosion after a
period of storage.
Finally, 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.
Caution:
The rear crankshaft bearing of this engine uses a
special plastic retainer. If the front housing needs
to be heated to remove or replace the bearing, do
not allow the bearing to exceed 120˚C (248˚F),
otherwise it may be damaged and rendered
unserviceable.
18

RACING ENGINE PARTS
(71608001)
(71605200)
(72106160)
(72103020)
(72103310)
(71530200)(71521000)
O.S. GENUINE PARTS & ACCESSORIES
O.S. Glow Plug 12TR Exhaust Header Pipes
For Super10 Class
No.8
R5 Super Joint Tube 15
T-1020 Tuned Silencer
Crankshaft Clamp
1521 Long Socket Wrench
With Plug Grip
φ3
(73300305)
φ7
(73300712)
φ12
(73301212)
Dust Cap Set
For Carburettor Nipple
For T-1020 Tuned
Silencer
For 10J,10E-M
Carburettor
Header Pipe Spring
(72106172)
(72106170)
For Pure10 Class Header Pipe Spring
(72106172)
Short
Long
(72106180)
For Pure10 Class Header Pipe Spring
(72106172)
(72103030)
T-1030 Tuned Silencer
19
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