Adjustment Of Engine Idling Speed; Fuel Injector; Fuel Injector Maintenance - Piper APACHE PA-23-235 Service Manual

PIPER AZTEC SERVICE MANUAL
e. Now advance the screw to a midway position between the lean and rich fuel
mixture; the RPM of the engine will reach a maximum speed for idle mixture
settings.
8-46. ADJUSTMENT OF ENGINE IDLING SPEED.
a.
Pull back the cockpit throttle control lever until, it is completely aft and in
the closed position. Observe the engine speed on the tachometer.
b. Adjust the idle adjustment screw to obtain from 550 to 600 RPM. Rotate
screw clockwise to increase the speed of the engine; counterclockwise to decrease
engine speed.
The screw is located on the throttle arm.
NOTE
One complete revolution of the carburetor idle screw
provides a variation of approximately 100 RPM in idling
speed.
8-47. FUEL INJECTOR. (Serial Nos. 27-2322 and up.)
CAUTION
Extreme caution should be exercised when handling or
working around the injector to prevent oil or fuel from
entering the air sections of the injector. As explained
previously, damage to the air diaphragm will result. Fluid can
easily enter the air section of the injector through the impact
tubes or the annular groove around the venturi. For this
reason, a protective plate should be installed on the scoop
mounting flange when performing routine maintenance on
the engine, such as washing down the engine and air scoop,
servicing the air filter (surplus oil on the element), or when
injecting preservative into the engine prior to storing or
shipping.
8-48. FUEL INJECTOR MAINTENANCE.
a.
In general, little attention is required between injector overhauls. How-
ever, it is recommended that the following items be checked during periodic in-
spection of the engine.
1. Check tightness and lock of all nuts and screws which fasten the injector
to the engine.
2. Check all fuel lines for tightness and evidence of leakage. A slight fuel
stain adjacent to the air bleed nozzles is not cause for concern.
3. Check throttle and mixture control rods and levers for tightness and
lock.
POWER PLANT
Reissued: 2/18/81
3C1