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O.S. SPEED Silicone Fuel Line
The connection between the fuel tank and the engine.
ID. 2.5mm Length 1000mm
Long Socket Wrench With Plug Grip
Recommended for easy removal and replacement of the
angled and recessed glowplug, the O.S.Long Socket
Wrench incorporates a special grip.
BASIC ENGINE PARTS
Cylinder head
Carburetor
Type 70D
Propeller nut
Drive Hub
Propeller washer
Propeller Locknut
Crankshaft
INSTALLATION
It is suggested to use as heavy and rigid as possible
engine mounting for highest performance and safe
running. Install the engine on a plastic mount using at
least 4mm steel screws, such as Allen type, with
locknuts, for bolting the engine to the bearers.
Make sure that these mounting beams are
accurately aligned and firmly integrated with the
airframe, reinforcing the adjacent structure to absorb
vibration. Use 4mm or larger steel screws,
preferably Allen type hexagon socket head cap
screws, with washers and locknuts, for bolting the
engine to the bearers.
O.S. Radial Motor Mount
A special O.S. radial motor mount (Code No.71904200)
is available, as an optional extra, for use where firewall
type mounting is required.
THROTTLE LINKAGE
Before connecting the throttle to its servo, make sure
that the throttle arm and linkage safely clear any
adjacent part of the airframe structure, etc., as the
throttle is opened and closed. Connect the linkage so
that the throttle is fully closed when the transmitter
throttle stick and its trim lever are at their lowest
settings and fully open when the throttle stick is in its
fully-open position. Carefully align the appropriate holes
in the throttle arm and servo horn so that they move
symmetrically and smoothly through their full travel.
INSTALLATION OF SILENCER AND ADAPTORS
Secure the silencer to the engine by means of two
retaining screws supplied after the engine is securely
mounted to a test bench or a model.
The exhaust outlet of the silencer can be rotated by 90
degrees the following manner:
1 )
Loosen the locknut and assembly screw.
2 )
Set the exhaust outlet at the required position by
rotating the rear part of the silencer.
3 )
Re-tighten the assembly screw, followed by the
locknut.
It is recommended to seal the fitting faces of engine
exhaust and silencer with silicone sealant.
Assembly screw
Baffle plate
Exhaust
pressure nipple
Gasket
In case of installing the silencer direct to
(optional extra)
the engine
After the engine is securely mounted to a model
or a test bench, secure the silencer to the
engine by means of two retaining screws
(M4x45) supplied.
In case of installing the silencer with the
extension adaptor to the engine
Secure the silencer and the extension adaptor
Glowplug
to the engine by means of two retaining screws
(M4x90) supplied.
In case of installing the silencer with the
90 degree adaptor to the engine
First secure the silencer to the 90 degree adaptor
by means of two retaining screws (M4x20).
Then, secure the assembly to the engine by
means of two retaining screws (M4x45).
Cover Plate
FUEL TANK LOCATION
Make sure that the tank is well rinsed out with
Beam Mount
methanol or glow fuel before installation and that
Crankcase
the pickup weight is well clear of the bottom of the
tank when held vertically.
The Fuel line pickup weight should be 10mm away
from the back of the tank.
Attention to
tank height
MIXTURE CONTROLS
Two mixture controls are provided on this Carburetor.
The Needle Valve
When set to produce maximum power at full throttle,
this establishes the basic fuel/air mixture strength. The
correct mixture is then maintained by the carburetor's
built-in automatic mixture control system to cover the
engine's requirements at reduced throttle settings.
The Mixture Control Valve
This meters fuel flow at part-throttle and idling speeds to
ensure reliable operation as the throttle is opened and
closed. The Mixture Control Valve is factory set for the
approximate best result. First run the engine as received
and readjust the Mixture Control Screw only if necessary.
STARTING
Be sure to use an electric starter to start the engine.
Starting procedure is as follows:
1.
Fill the fuel tank with fuel. When filled, prevent fuel
flowing into the carburetor with a commercially
available fuel stopper, etc. Release the stopper
before starting the engine.
2.
Make sure that plug element glows red, and install
the plug in the cylinder head.
3.
Check that the needle-valve is closed. (Do not
overtighten.) Now open the needle-valve counter-
clockwise 2.5 to 3 turns to the starting setting.
Can be rotated
by 90 degrees.
4. Open the throttle approx. one-quarter.
Set at this point
Fully closed
position
Locknut
5.
Apply the starter and press the starter switch for 5-6
seconds to prime the engine.
6.
Connect battery leads to glowplug.
Locate the fuel tank as close to the engine as possible to minimize fuel level pressure variation.
For carburetor
Mixture Control Valve
Needle Valve
Mark Close
Turn needle-valve clockwise to close
(for leaner mixture)
Turn needle-valve counter-clockwise
to open (for richer mixture)
Open
(This is to avoid unnecessarily
high r.p.m. when the engine starts.)
Fully opened position
1
3
4
4
Note:
Do not use the extension adaptor and the 90
degree adaptor at the same time (simultaneously),
or they may break.
E-5020 Silencer
90 Adapter
E-5020 Silencer
Extention Adapter
Position the fuel tank so that approximately 1/3 of the
tank height is above the center line of the needlevalve.
Be sure to use a pressurized fuel system by
connecting the muffler pressure nipple to the
vent-pipe of the fuel tank.
For Silencer
Carburetor Center Line
Plug
Approx. 10mm
(commercially available)
Bring electric starter into contact with spinner-nut or
7.
spinner and depress starter switch for one or two
seconds. Repeat if necessary. When the engine
starts, withdraw the starter immediately.
Attention :
Do not choke the carburetor air intake when applying
the starter. This could cause an excessive amount of
fuel to be drawn into the cylinder which may initiate a
hydraulic lock and damage the engine.
VERY IMPORTANT!
Before being operated at full power (i.e. at full-throttle
and with the needle-valve closed to its optimum setting)
the engine must be adequately run-in, otherwise there is
a danger of it becoming overheated and damaged.
How to stop the engine
Pull down the throttle lever and trim lever on the
transmitter fully.
Note:
Make sure that the throttle linkage is set so that the
throttle is fully closed when the throttle lever as well
as trim lever on the transmitter are fully pulled down.
RUNNING-IN ("Breaking-in")
All internal-combustion engines benefit from extra care
when they are run for the first few timesknown as
running-in or breaking-in. This allows the working parts
to mate together under load at operating temperature.
Therefore, it is vitally important to complete the
break-in before allowing the engine to run continuously
at high speed and before finalizing carburetor
adjustments. However, because O.S. engines are
produced with the aid of the finest modern precision
machinery and from the best and most suitable
materials, only a short and simple running-in
procedure is called for and can be carried out with the
engine installed in the model.
The process is as follows.
1.
Install the engine with the propeller intended for your
model. Open the needle-valve to the advised
starting setting and start the engine. If the engine
stops when the glow plug battery is disconnected,
open the needle-valve to the point where the engine
does not stop. Run the engine for one minute with
the throttle fully open, but with the needle-valve
adjusted for rich, slow "four-cycle"operation.
Approx.
1/3
Approx.
2/3
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