Piper PA-28-161, Maintenance Manual

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PIPER AIRCRAFT, INC.
PA-28-161, WARRIOR III
MAINTENANCE MANUAL
PAGE 2
Nov 30/06
4K14
73-20-00
(3) Turn the idle mixture adjusting screw (1) located near the rear of the carburetor, clockwise,
leaning the fuel mixture. Continue to do this until the engine begins to run roughly, at which
time the engine speed will decrease.
(4) Turn the screw counterclockwise until the engine runs smoothly again. Continue to turn the
screw in the same direction until the engine begins to run roughly once more. At this point, the
fuel mixture will be too rich and engine speed will decrease again.
(5) Now advance the screw to a midway position between the lean and rich fuel mixture: the RPM
of the engine will reach a minimum speed for idle mixture settings.
C. Idle Speed Adjustment
(1) Pull back the cockpit throttle control lever until it is completely aft and in the closed position.
Observe the engine speed on the tachometer.
NOTE: One complete revolution of the carburetor idle screw provides a variation of
approximately 100 RPM in idling speed.
(2) Adjust the idle speed adjustment screw to obtain from 550 to 650 RPM. Rotate the screw
clockwise to increase the speed of the engine; counterclockwise to decrease the engine
speed. The screw is located on the throttle arm.
2. Engine Controls (Refer to Figure 2.)
Throttle and mixture controls are adjusted so that when the throttle arm on the carburetor is rotated
forward against its full throttle stop and the mixture control is rotated forward against its full rich stop;
the cockpit control levers of the throttle and mixture should be within 0.03 to 0.12 of an inch of the
instrument panel stop.
A. Throttle Control Adjustment
(1) At the carburetor:
(a) Set the throttle arm on the carburetor against the full throttle stop.
(b) Disconnect the rod end of the throttle control cable from the throttle arm.
(c) Loosen the jam nut that secures the rod end.
(2) Adjust the linkage by rotating the rod end on the carburetor end of the throttle cable until the
cockpit throttle lever is within 0.03 to 0.12 of an inch of the instrument panel stop when the
throttle arm on the carburetor is against the full throttle stop.
(3) Reconnect the rod end to the control arm and safety.
(4) Check security of cable casing attachments.
(5) Pull the throttle lever in the cockpit full aft to determine that the idle screw contacts its stop.
B. Mixture Control Adjustment
(1) At the carburetor:
(a) Set the mixture arm on the carburetor against the full rich stop.
(b) Disconnect the rod end of the mixture control cable from the mixture arm.
(c) Loosen the jam nut that secures the rod end.
(2) Adjust the linkage by rotating the rod end on the carburetor end of the mixture cable until the
cockpit mixture lever is within 0.03 to 0.12 of an inch of the instrument panel stop when the
mixture arm on the carburetor is against the full rich stop.
(3) Reconnect the rod end to the control arm and safety.
(4) Check security of cable casing attachments.
(5) Pull the mixture lever in the cockpit full aft to determine that the mixture control arm contacts
its lean position stop.