O.S. Engines 91FX-HGL - Manual (Page 21)

INSTALLATION OF THROTTLE SERVO
After the engine in the helicopter, please observe the
following recommendations when linking the throttle
servo to the carburetor.
Locate the servo so that its output arm and the throttle
pushrod are, as closely as possible, directry in line with
carburetor's throttle arm, as shown.
Servo output arm
Throttle control rods A and B should be of equal length.
Set the linkage so that the servo output arm and throttle
arm are parallel when the throttle stick on the transmitter
is at its mid position. If differential throttle movement is re-
quired, make necessary adjustment at the transmitter.
Throttle arm
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