Piper Navajo PA-31 Service Manual page 490

PIPER NAVAJO SERVICE MANUAL
e. Connect the throttle
and mixture control cables to the injector.
Rig con-
trols per paragraph
8-45.
f. Replace cowling per paragraph
8-6.
g.
Adjust idle speed and mixture per paragraph
8-46.
8-45. ADJUSTMENT OF THROTTLE
AND MIXTURE CONTROLS.
The throttle
and mixture controls are adjusted so that when the throttle arm on the injector
is
rotated
forward against its full throttle
stop and the mixture arm is rotated for-
ward against its full rich stop, their
respective cockpit control levers
should be
.062 to . 125 inch in from their full forward
stops, which are located in the con-
trol pedestal.
a. At the injector,
disconnect the throttle and/or
mixture control cable end
from its control
arm.
b. Loosen the jam nut securing
the cable end.
c. Adjust the linkage by rotating
the cable end to obtain the . 062 to . 125 inch
spring back of the cockpit control leverwhen
the throttle or mixture
control arm
contacts
its stop.
d. Reconnect the cable end to its control arm and secure jam nut.
e. Pull the throttle and mixture control lever in the cockpit full aft to ascertain
that the injector idle screw contacts
its stop and the mixture control arm contacts
its lean position.
8-46. ADJUSTMENT OF IDLE SPEED AND MIXTURE.
a.
Start the engine and warm up in the usual manneruntiloil
and cylinder head
temperatures are normal.
b. Check magnetos.
If the "mag-drop" is normal,
proceed with idle adjust-
ment.
c. Close the throttle to idle. If the RPM changes appreciably after making the idle mix-
ture adjustment during the succeeding steps, readjust the idle speed to the desired RPM
(600/650 RPM).
NOTE
The idle mixture
must be adjusted with the fuel boost
pump "ON."
d. When the idling speed has been stabilized,
move the cockpit mixture control
lever with a smooth,
steady pull toward the "Idle Cut-Off" position and observe
the tachometer for any change during the "leaning" process.
Caution must be ex-
ercised to return
the mixture control to the "Full Rich" position before the RPM
Revised: 3/11/81
POWER PLANT
2116