O.S. Engines 12TZ(P) - Manual (Page 10)

18
Turn the engine with starter box to draw he
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.
When the engine starts, first allow it to
operate in short runs at the very rich starting
settings, with the glowplug battery still
connected and the driving wheels clear of
the ground. The rich mixture will, under
these conditions, provide adequate
lubrication and cooling, indicated by profuse
smoke from the exhaust.
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.
Attention:
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.
Swith on the transmitter and make sure that
each linkage moves correctly.
19
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. 2
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 Mixture Screw
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. 2 liters of fuel have
been consumed.
Warning!
Do not touch rotating
parts, engine and silen-
cer 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, 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 carburetor.
Note:
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 work-
ing parts (e.g. piston/cylinder liner assem-
bly) being replaced or the fuel being
changed, especially to high nitro fuel, the
complete running-in should be repeated.
Fuel