O.S. engine OSM11532 Owner's Instruction Manual page 18

Priming quantity
After fuel has been drawn to the carburettor, flip the
propeller two more revolutions, with intake choked, to
draw fuel into engine.
Above procedure is called priming.
NOTE (IMPORTANT)
The quantity of fuel drawn into the engine by
priming is an important factor in starting the
engine successfully.
When the engine is being started for the first time,
turn the propeller two revolutions after fuel reaches
the fuel inlet, as described above. However, when re-
starting the engine immediately after a run, one
revolution, or even no priming at all may be required.
The engine's requirements will be quickly learned
with experience.
9
Do not energize the glowplug at this stage.
Turn the propeller 3 to 4
turns counter-clockwise
smartly by finger in the
direction of arrow. Turn
approx. 10 turns instead
when the engine is cold.
17