O.S. Engines 25LA - Manual (Page 23)

Once the optimum needle-valve setting has been
established (see "Needle-valve adjustment-
Summary") the procedure for starting is simplified as
follows:
1) Open the needle-valve one half-turn (180˚) from
the optimum setting.
2) Open the throttle fully, place your finger over the
carburettor intake and rotate the propeller through
two revolutions to prime the engine.
3) Set the throttle one-third open from the fully closed
position, energize the glowplug and apply the
starter. When the engine starts, re-open the
throttle and re-adjust the needle-valve to the
optimum setting.
19 How to stop the engine
Close the throttle to reduce to the lowest possible r.p.m.
Close
With the transmitter throttle trim lever fully retarded, adjust the
throttle servo linkage so that the throttle rotor is fully closed
(i.e.engine stopped) when the stick is fully retarded.
Subsequent starting procedure
18
Note: When re-starting the engine on the same
day, provided that atmospheric conditions have
not changed significantly, it may be practicable to
re-start the engine on its optimum (running)
setting. Also, if the engine is being re-started
immediately after a run (i.e.hot), priming should
not be necessary.
22