O.S. engine MAX-91SZ-Hring Owner's Instruction Manual page 15

ADJUSTING CHART
High Speed Needle Valve - 2 turns opened from fully closed position.
Medium Speed Needle Valve - 2 turns opened from fully closed position.
Start the engine
Warm up the engine
Observe the mixture condition while "floating" the model
Lean mixture
Turn the Idle Mixture
Control Screw counter-
Idling OK
clockwise 5 degrees
Observe the hovering mixture condition
Lean mixture
Open the High Speed
Needle Valve
Hovering OK
(Turn counter-clockwise)
Land the model
Idle for approx: 10 seconds, then reopen throttle to
observe transition ("Float" the model)
Lean mixture
Turn the Idle Mixture
Control Screw counter-
Idling OK
clockwise 5 degrees
High Speed Flight
Lean mixture
Open the High Speed
Needle Valve
High Speed Flight OK
(Turn counter-clockwise)
Fine tuning of idling mixture
Lean mixture
Turn the Idle Mixture
Idling OK
Control Screw counter-
clockwise 5 degrees
Fine tuning of hovering mixture
Lean mixture
Open the Medium
Hovering OK
Speed Needle Valve
Adjustment completed
Rich mixture
Turn the Idle Mixture
Control Screw
clockwise 5 degrees
Rich mixture
Close the High Speed
Needle Valve
(Turn clockwise)
Rich mixture
Turn the Idle Mixture
Control Screw
clockwise 5 degrees
Rich mixture
Close the High Speed
Needle Valve
(Turn clockwise)
Rich mixture
Turn the Idle Mixture
Control Screw
clockwise 5 degrees
Rich mixture
Close the Medium
Speed Needle Valve