O.S. Engines FS-40S - Manual (Page 17)

Close
Open
4 Opening and closing of the needle-valve
Turn needle-valve clockwise to close (for
leaner mixture).
Turn needle-valve counter-clockwise to
open (for richer mixture).
Starting
Turn the needle-valve in the direction
of arrow slowly, without forcing, until it
stops.
5 Setting the needle-valve
The position where the needle-valve
stops is the fully closed position. It may
be convenient to remember the position
of the mark or set-screw at this time.
Set-screw
Turn the needle-valve in the direction
of arrow from the closed position.
FS-26S (3 to 3-1/2 turns)
FS-40S (2-1/2 to 3 turns)
6 Open the throttle fully
Fully closed position
Fully opened position
Throttle
Open
Close
Fuel will flow from tank to
carburettor as propeller is
turned.
Close the air intake
by operating the
choke control.
Turn the propeller
four revolutions
while watching
fuel line.
Turn the propeller 3
to 4 turns counter-
clockwise smartly
by finger in the
direction of arrow.
Turn approx.
10 turns when the
engine is cold.
7 Priming
16