ABOUT THE ENGINE
STANDARD ACCESSORIES
Make sure that the propeller is well balanced. An
unbalanced propeller and/or spinner can cause serious
vibration which may weaken parts of the airframe or
affect the safety of the radio-controlled system.
Since the engine is intended to be started with an electric
starter, the addition of a spinner assembly for centering
the starter sleeve is desirable. Use a heavy-duty, well
balanced spinner either of metal or plastic.
Warning:
The choice of propeller depends on the design and
weight of the aircraft and the type of flying in which you
will be engaged. Determine the best size and type
after practical experimentation. As a starting point,
refer to the props listed in the accompanying table.
Slightly larger, or even slightly smaller, props than
those shown in the table may be used, but remember
that the propeller noise will increase, due to higher rpm
or if a larger-diameter / lower-pitched prop is used.
PROPELLERS
FUEL
Fuel Filter
BEFORE STARTING
It is recommended to install a good in-line filter between the
fuel tank and carburetor to prevent entry of foreign matter
into the carburetor.
To prevent the pickup from adhering to the tank wall
under suction and restricting fuel flow, slots may be filed I
the end of the weight. Alternatively, O.S. Non-Bubble
Weight is available as an optional extra.
O.S. Non-Bubble Weight
O.S. Super Filter (Fuel Can Filter)
Install a filter on the outlet tube of your refueling container to
prevent entry of foreign matter into fuel tank. O.S. ‘Super
Filters’ (large and small) are available as optional extras.
GlowPlug Igniter
Commercialy available handy glowplug heater in which
the glowplug battery and battery leads are integrated.
Fuel Pump
Alternatively, one of the purpose-made manual or
electric fuel pumps may be used to transfer fuel directly
from your fuel container to the fuel tank.
Electric Starter and Starter Battery
Required when starting the engine.
A fuel tank of approximately 350cc capacity is suggested.
This allows around 10-12 minutes flying time, dependent
upon the type of fuel used, the size of propeller and on
the amount of full-throttle to part-throttle operation
throughout the flight.
Fuel Tank
Never touch, or allow any object to come
into contact with, the rotating propeller
and do not crouch over the engine when
it is running.
Adjust the throttle linkage so that the engine stops
when the throttle stick and trim lever on the
transmitter are fully retarded. Alternatively, the
engine may be stopped by cutting off the fuel supply.
Never try to stop the engine physically.
Take care that loose clothing (ties, shirt sleeves,
scarves, etc.)do not come into contact with the
propeller. Do not carry loose objects (such as
pencils, screwdrivers, etc.) in a shirt pocket from
where they could fall through the propeller arc.
Do not start your engine in an area containing loose
gravel or sand. The propeller may throw such
material in your face and eyes and cause injury.
For their safety, keep all onlookers (especially small
children) well back (at least 20 feet or 6 meters) when
preparing your model for flight. If you have to carry the
model to the take-off point with the engine running, be
especially cautious. Keep the propeller pointed away
from you and walk well clear of spectators.
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 the propeller is casually
flipped over compression WITHOUT the glowplug
battery being reconnected. Remember this if you
wish to avoid the risk of a painfully rapped knuckle!
Always check the tightness of the propeller nut and
retighten it, if necessary, before restarting the engine.
Also, check the tightness of all the screws and nuts
before restarting the engine.
If you install a spinner, make sure that it is a precision
made product and that the slots for the propeller blades
do not cut into the blade roots and weaken them.
Preferably, use an electric starter. The wearing of
safety glasses is also strongly recommended.
Discard any propeller which has become split,
cracked, nicked or otherwise rendered unsafe.
Never attempt to repair such a propeller: destroy it.
Do not modify a propeller in any way, unless you are
highly experienced in tuning propellers for specialized
competition work such as pylon-racing.
Take care that the glow plug clip or battery leads do
not come into contact with the propeller. Also check
the linkage to the throttle arm. A disconnected
linkage could also foul the propeller.
After starting the engine, carry out any needle-valve
readjustments from a safe position behind the
rotating propeller. Stop the engine before attempting
to make other adjustments to the carburetor.
This engine was designed for model aircraft. Do not
attempt to use it for any other purpose.
Mount the engine in your model securely, following
the manufacturers' recommendations, using appropri-
ate screws and locknuts.
Be sure to use the silencer (muffler) supplied with the
engine. Frequent exposure to an open exhaust may
eventually impair your hearing. Such noise is also
likely to cause annoyance to others over a wide area.
Install a top-quality propeller of the diameter and pitch
specified for the engine and aircraft. Locate the
propeller on the shaft so that the curved face of the
blades faces forward-i.e. in the direction of flight. Firmly
tighten the propeller nut, using the correct size wrench.
If you remove the glowplug from the engine and
check its condition by connecting the battery leads to
it, do not hold the plug with bare fingers.Use an
appropriate tool or a folded piece of cloth.
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.
A weakened or loose propeller may disintegrate or
be thrown off and, since propeller tip speeds with
powerful engines may exceed 600 feet(180 metres)
per second, it will be understood that such a
failure could result in serious injury, (see 'NOTES'
section relating to propeller safety).
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.
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.
WARNINGS
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.
SIZE(DxP)
15x10-12, 16x8-10
SPINNER
MAX-
120AX
RING
Two versions are available, the one is without
silencer, extension adaptor and 90 degree adaptor
and the other is with all of them.
This is a high performance two stroke engine designed
for sport and scale models.
Crankcase and cylinder head are of aero-shape design
which give advantage of light weight, compact size.
The new 70D carburetor needlevalve assembly has
now been angled backward for safety.
New E-5020 silencer (POWER BOX) develops very
effective muffling. Also, the compact body enables it
to be fit with in most cowls.
Extension adaptor and 90 degree adaptor offer
various silencer installations.
Glow Plug No.8
E-5020 Silencer Extention Adapter
Needle Valve Extension Cable Set
Silencer Extention Adapter
Retaining Screw (M4x90 2pcs.)
E-5020 Silencer Assembly
Silencer Retaining Screw (M4x45 2pcs.)
E-5020 Silencer 90 Adapter
Silencer 90 Adapter Retaining
Screw (M4x20 2pcs.)
The 120AX should be operated on a methanol based fuel
containing not less than 18% (volumetric) castor oil, or a
top quality synthetic lubricant (or a mixture of both), plus
a small percentage (5-20%) of nitromethane for improved
flexibility and power. (The carburetor is adjusted a little on
the rich side at the factory for a fuel containing 20%
lubricant and 15% nitromethane.) Some commercial
fuels also contain coloring additives as an aid to fuel level
visibility. In some cases, these additives have indicated
slightly negative effects on the performance. We would
suggest that you use such fuels only if you are satisfied
that they do not adversely affect running qualities when
compared with familiar standard fuels.
When changing to a fuel brand or formula that is different
from the one to which you are accustomed, it is a wise
precaution to temporarily revert to in-flight running-in
procedures, until you are sure that the engine is running
entirely satisfactorily.
2 CYCLE ENGINE
600917300000
