Piper COMANCHE PA-24-180 Service Manual page 375

ASI
FIGURE 7A-13. FUEL AIR BLEED NOZZLE
d
When the idling speed has been stabilized. mo\e the cockpit mixture control with a smooth. stead!
pull toward the "Idle Cut-Off" position and observe the tachometer for any change during the "leaning"
process. Caution must be exercised to return the mixture control to the "Full Rich" position before the
RPM can drop to a point where the engine cuts out An increase of more than 50 RPM while leanng out"
indicates an excessively rich idle mixture. An immediate decrease in RPM (if not preceded by a momentary
- increase) indicates the idle mixture is too lean
e If the abo\e indicates that the idle adjustment is too rich or too lean. turn the idle mixture
adjustment in the direction required for correction. and check this new position b\ repeating the abo\e
procedure
Make additional adjustments as necessary Each time the adjustment is changed. the engine
should be run up to 2000 RPM to clear the engine before proceeding with the RPM check Make final
adjustment of the idle speed adjustment to obtain the desired idling RPM with closed throttle The abo\e
method aims at a setting that will obtain maximum RPM with minimum manifold pressure In case the
setting does not remain stable. check the idle linkage: any looseness in this linkage would cause erratic
idling in all cases. allowance should be made for the effect of weather conditions and field altitude upon
idling adjustment
7A-63 Fuel Air Bleed Nozzles.
7A-64 Removal Of Fuel Air Bleed Nozzles. The nozzles must be carefully remo\ed as the\ or the
cxlinders may be damaged
a Lift the side access panel of the engine cowling
b
Disconnect the fuel line from the nozzle
c Carefully remo\e the nozzle using the correct size deep socket
d.
Clean and inspect the nozzle as given in paragraph 7A-65.
ISSUED: 8/18/72 POWER PLANT
PIPER COMANCHE SERVICE MANUAL
2D17