O.S. Engines 70SZ-H - Manual (Page 9)

16
In case the engine does not stop.
Hold the rotor head, and pinch the fuel line to stop the
fuel supply. If it still does not stop, pull off the fuel line
from the carburetor.
It is necessary to readjust the throttle linkage so that
the carburetor rotor is fully closed when the throttle
stick and throttle trim on the transmitter are fully
pulled Down.
Stopping the engine
Fully pull down the throttle trim on the transmitter.
Starting
Connect the battery to the glowplug and start the
engine by applying the starter. When started, switch
off the starter and withdraw the starting shaft after
making sure the rotation of the starter shaft stops.
Preparation of starting
Make sure that the transmitter
throttle stick is at the fully closed
position and the throttle trim at center
position, and make sure that idle-up
switch on the transmitter is off. Hold
the rotor head by hand so that rotor
cannot rotate when the engine is Started. Also, steady
the model with a foot on the landing gear skid.
7.
8.
9.
NOTE:
If the throttle response is poor or the engine
stops due to a temporarily over-rich mixture im-
mediately after the engine is started, pinch the
fuel line for one or two seconds until the engine
r.p.m. increase and the engine runs steadily.
Reminder!
Never touch, or allow any object to
come into contact with, the rotating
rotor.
17
All internal-combustion engines benefit, to some
degree, from extra care when they are run for the first
few times known as running-in or breaking-in.
This is allows the working parts to mate together
under load at operating temperature.
However, because O.S. engines are made with the
aid of the finest modern precision machinely and from
the best and most suitable materrials, only a very
short and simple running-in procedure is required and
can be carried out with the engine installed in the
model. For the first few flights with a new engine i.e.
while the engine is being run-in set the needle-
valve for a slightly rich mixture not excessively rich
as this may result in poor throttle response and cause
the engine to stope. About one half turn open from
the nomal setting will usually suffice.
RUNNING-IN ("Breaking-in") ADJUSTMENT
Please observe the following before beginning to
make any adjustment.
High-Speed Needle Valve. Turn this approximately
30 degrees (3 to 4 click) at a time, when making
initial adjustments; then in steps of approximately
15 degrees (1 to 2 clicks) when making final
adjustments.
Medium-Speed Needle Valve. Turn approximately
45 degrees (4 to 5 click) at a time.
Idle Mixture Control Screw. Turn approximately 10
degrees at a time. It turns approximately 90
degrees both side from the center. Turn left to
enrich the idle mixture and turn right to lean the idle
mixture.