User Manual

It is of vital importance, before attempting to operate your
engine, to read the general 'SAFETY INSTRUCTIONS
AND WARNINGS' in the following section and to strictly
adhere to the advice contained therein.
Also, please study the entire contents of this
instruction manual, so as to familiarize yourself with
the controls and other features of the engine.
SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE
The advice which follows 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.
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 or abused. 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.
WARNINGS
NOTES
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.
Model engines generate considerable
heat. Do not touch any part of your engine
until it has cooled. Contact with the
muffler (silencer), cylinder head or
exhaust header pipe, in particular, may
result in a serious burn.
Never operate your engine in an enclosed space.
Model engines, like automobile engines, exhaust
deadly carbon-monoxide. Run your engine only in
an open area.
Install 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.
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.
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.
Before starting the engine, always check the
tightness of all the screws and nuts especially those
of joint and movable parts such as throttle arm.
Missing retightening the loose screws and nuts
often causes the parts breakage that is capable of
harming you.
ENGINE CONSTRUCTION
With this engine, the piston will feel tight at the
top of its stroke (TDC) when the engine is cold.
This is normal. The cylinder bore has a slight
taper. The piston and cylinder are designed to
achieve a perfect running clearance when they
reach operating temperature.
Piston
Cylinder
Liner
Crankshaft
Near TDC
Slight taper
When the engine is cold.
When the engine is hot.
NOTES WHEN APPLYING AN ELECTRIC STARTER
Do not over-prime. This could cause a
hydraulic lock and damage the engine on
application of the electric starter.
If over-primed, remove glowplug, close
needle-valve and apply starter to pump out
surplus fuel. Cover the head with a rag to
prevent any pumped out fuel from getting into
your eyes.
As delivered, the engine has the carburetor
lightly fit into its intake. Secure it changing its
angle according to the car chassis.
NOTE
Please do not run on a public street, this
could cause serious accidents, personal
injuries and/or propetry damage.
Please do not run near pedestrians or small children.
Please do not run in small or confined areas.
Please do not run where loud noises can disturb
others, such as hospitals and residential areas.
While Operating
ABOUT THE PRODUCT
FUEL
Generally, it is suggested that the user selects a fuel that is
commercially available for model two-stroke engines and
contains 10-30% nitromethane. As a starting point, we
recommend a fuel containing 20% nitromethane, changing to
a fuel containing more nitro if necessary. When the brand of
fuel is changed, or the nitro content increased, it is advisable
to repeat the running-in procedure referred
to in the RUNNING-IN paragraphs. Please
note that with high-nitro fuels, although
power may be increased for competition
purposes, glowplug elements do not last as
long and engine life will be shortened.
Items necessary for starting
TOOLS, ACCESSORIES, etc.
The following items are necessary for operating the engine.
FUEL FILTER
To installed in the fuel line between fuel
tank and carburetor to prevent foreign
matter from entering the carburetor.
GLOWPLUG IGNITER
Commercialy available handy glowplug
heater in which the glowplug battery and
battery leads are integrated.
STARTER BOX
For starting the engine.
FUEL PUMP
For filling the fuel tank, a simple, polyethylene
"squeeze" bottle, with a suitable spout, is required.
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.
TOOLS
O.S. SPEED DRIVER TOOLS
O.S. SPEED PLUG WRENCH
O.S. SPEED
CLUTCH WRENCH & ADJUSTER
O.S. SPEED FLYWHEEL KEY
O.S. SPEED FLYWHEEL PULLER
Outer Head
Crankcase
Mounting Lugs
Exhaust
Cover Plate
Carburetor
Type 12D2
Crankshaft
BASIC ENGINE PARTS
Crankshaft Bearing (Front)
Metering Needle
Throttle Stop Screw
Needle Valve
Ball Link
Dust Cover
CARBURETOR CONTROLS
The Needle-Valve (Adjusted at the factory):
Three adjustable controls are provided on this
carburetor.
For adjusting the mixture strength when the throttle
is fully open.
The Throttle Stop Screw (Adjusted at the factory):
For setting the minimum idle speed:
For adjusting the mixture strength at part-throttle
and idle speed, to obtain steady idling and smooth
acceleration to mid speed.
The Metering Needle (Adjusted at the factory):
NOTE: Readjustment may be necessary, occasionally
to allow for changes in fuel formula, gear ratio or
clutch engagement point.
INSTALLATION OF THE CARBURETOR
As delivered, the engine has its carburetor lightly
installed in the intake boss. Secure it as follows.
Loosen the retainer screw, rotate the carburetor to its
correct position and make sure that it is pressed well
down into the intake boss, compressing the rubber
gasket, before retightening screw.
1.
2.
Rotate the retainer nut
gently until it stops.
Tighten a further
60-90
Rotate the retainer screw gently until it stops, then
tighten a further 60-90 .
Do not overtighten the screw as this will damage the
carburetor body.
ENGINE INSTALLATION
Running- in is a procedure for an engine to come
close to actual running conditions (fuel, r.p.m.,
engine temperature, etc.).
Excessively rich running and prolonged low speed
running should be avoided. Prolonged low speed
running and low temperature running may result
in the oil in the fuel becoming gelled and the
piston / liner becoming stuck together.
RUNNING-IN ('Breaking-in)
PRESSURIZED FUEL SYSTEM
The following procedure is suitable when a fuel
containing 30% nitro-methane is used.
Fill the tank completely with fuel.
STARTING THE ENGINE & RUNNING-IN ('Breaking-in)
Turn the needle-valve clockwise until it stops.
This is the fully closed position. Do not force it to
turn further.
Needle Valve
Open
Close
The carburetor is set as shown below at the factory.
Start the engine as it is.
The needle-valve is set approx. 2.5 turns opened
from the fully closed position.
Throttle is set approx. 0.5mm open.
Approx. 0.5mm open factory setting.
REALIGNMENT OF METERING NEEDLE
In the course of making carburetor adjustments, it is just
possible that the Metering Needle may be inadvertently
screwed in or out too far and thereby moved beyond its
effective adjustment range. The basic positions can be
found by rotating the Metering Needle until its slotted
head is flush with the ball link body.
Turn the engine with starter box to draw fuel into
the engine.
Fuel
Deliver fuel into the carburetor.
Fuel tank side
Now connect glowplug battery lead to heat the plug
filament and start the engine.
Switch on the transmitter and make sure that each
linkage moves correctly.
approx 1mm
Set the throttle opening a little wider that the factory
setting by adjusting the Throttle Stop Screw.
When the engines does not start or stops right
after being started, try the followings.
Set the needle-valve approx. 2 turns open from the
fully closed position. Do not force the needlevalve to
turn beyond a lightly closed position.
When the engine starts, warm it up by repeatedly
increasing the rpm to medium speed and back
again to a fast idle with the mixture set very rich,
the glowplug connected, and the driving wheels
clear of the ground. The rich mixture will provide
adequate lubrrication and cooling indicated by
profuse exhaust smoke.
throttle trigger
Attention:
It is vitally important to set the
throttle at the correct position
before starting the engine. If
the engine is allowed to run
with the throttle too far open
under ''no load'' conditions
(i.e. with the driving wheels not in contact with the
ground) it will rapidly over-heat and may be
seriously damaged.
Note:
In the event of any major working parts (e.g.
piston/cylinder liner assembly) being replaced or
the fuel being changed, especially to high nitro
fuel, the complete running-in should be repeated.
Warning!
Do not touch rotating parts, engine and silencer
when stopping the engine as they become very
hot, and contact with them may result in a serious
burn.
To stop the engine, close the throttle to idle speed and
shut it off completely with the trim lever on the
transmitter then cut off the fuel supply by pinching the
fuel delivery tube to the carburetor.
How to stop the engine
Standard accessories
Exhaust Seal Ring 1piece
Fuel Inlet
Needle Holder
Thermo Insulator
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.
Engine Mount
When installing the engine on the chassis, note the
following points.
(Chamfer inside edges of bearers when the engine
mount edges interfere with the engine. Do not
chamfer the engine.)
File
Chassis
Chamfer inside edges of bearers.
Do not allow bottom of
crankcase to touch chassis.
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 are in alignment with the
mounting holes.
Chassis
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.
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 carburetor, means that the
fuel 'head' at the carburetor can vary and upset
running.Therefore,it is recommended that a muffler
pressurized fuel feed system be used.
Temporarily remove the glowplug to check that it
glows bright red when energized.
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 15˚ and try again.
Run the car on the track until one tank of fuel has
been consumed, then close the Needle-Valve 15˚ and
run the car for 3 to 5 full tanks of fuel.
Repeat this procedure until approx. 1 liters 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
Metering Needle 45˚.
Needle
The position of the needle-valve
when starting the engine.
Close the needle-valve approx.
15˚ after running the vehicle for
3 to 5 full tanks of fuel.
Repeat this procedure until
approx. 1 liters of fuel have
been consumed.
Fuel
1/10 class for car
Dust Cap 3mm, 16mm(2pcs.)
Glow Plug P4
T-type head (Turbo head) 1piece
MAX-12TG Ver.IV is a successor of MAX-12TG Ver. III.
The new engine boasts the same connecting of OS
SPEED T12 series, which is more durable and racing
specification. A crankcase and an outer head are
newly designed.
A refined piston enables smoother acceleration
suitable for sports driving.
O.S. SPEED PISTON PIN RETAINER PLIERS
MAX-12TG Ver.IV
Slide Valve
Carburetor Body
Metering Needle
Flush with the ball link body.
Ball Link
[Standard Position]