O.S. Engines Rotary 49PI - Manual (Page 15)

Fill the fuel tank and open the needle-valve 2-3
turns from the closed position.
STARTING
Prime the engine fairly liberally with fuel
through the carburettor. Turn the propeller
through one complete revolution and prime
again. Repeat this procedure once more so
that all three chambers, formed between the
rotor flanks and housing, are primed. Now
rotate the prop through several revolutions so
that any excess of fuel is blown through the
exhaust port. This will leave the chambers with
just about the correct proportion of fuel and air
for starting.
An alternative priming procedure, that some
users may find preferable when an electric
starter is being used, is to simply finger-choke
the intake (throttle fully open) while turning the
prop for six revolutions.
Now close the throttle to between one-quarter
and one-third open, connect glowplug lead and
apply electric starter.
After starting, allow the engine to warm up for
5~6 seconds, then remove the plug lead, open
the throttle fully and adjust the needle-valve.
Adjust for rich, reduced-rpm running when the
engine is new (see paragraph below on
"Running-in" ) : otherwise adjust for full power.
When re-starting the engine hot, do not prime:
simply close the throttle and apply the starter:
it will burst into life again immediately.
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