Piper COMANCHE PA-24-180 Service Manual page 376

7A-65. Cleaning and Inspection of Fuel Air Bleed Nozzles.
a.
Clean the nozzles with acetone or Methylethylketone (MEK) and blow out all foreign particin
with compressed air in the direction opposite that of fuel flow. Do not use wire or other hard objects to
clean orifices.
b.
Inspect the nozzle and cylinder threads for nicks, stripping or cross-threading and battered or
rounded hexagons.
c.
Inspect and replace nozzle O-rings found to be cracked, brittle or distorted. Refer to Lycoming
Service Instructions No. 1275 for detailed test procedure of air bleed nozzles.
7A-66. Installation of Fuel Air Bleed Nozzle.
a.
It is important for the nozzles to be correctly positioned with the air bleed hole facing upward.
b.
Install the nozzles and tighten to a little less than 60 inch-pounds torque.
c.
Continue to tighten the nozzles until the letter or number stamped on the hex of the nozzle body
points down. In this position the air bleed hole will face upward.
NOTE
Do not exeed 60 inch-pounds torque on nozzles when aligning air
bleed hole.
d. Connect fuel line to nozzle.
CAUTION
Start nozzles and line couplings by hand to prevent the possibility of
cross-threading.
e. Install engine cowling.
7A-67. Ignition System
7A-68. Magneto.
CAUTION
Ascertain that the primary circuits of both magnetos are grounded
before working on the engine.
7A-69. Inspection Of Magnetos. At time of engine inspection or when a magneto has been removed from
the engine, the following checks may be performed. Each step in the check list is keyed by number to a
pan shown in Figure 7A-14.
1.
Inspect distributor block contact springs. If broken or corroded, they should be replaced.
2.
Inspect oil felt washer. It should be saturated with oil. If dry, check for worn bushing. If O. K., add
No. 30 oil.
3.
Inspect distributor block for cracks or burned areas. The wax coating on the block should not be
removed. Do not use solvents.
4.
Look for excess oil in breaker compartment. If present, it may mean a bad oil seal or oil seal
bushing at drive end. Check manufacturer's overhaul procedure.
5.
Look for frayed insulation or broken wire strands in leads in back of magneto. See that terminals
are secure. Be sure wires are properly positioned. The position of the leads in the 200 series breaker
compartment must be as shown in Figure 7A-15, otherwise, chafing or breaking may result.
POWER PLANT
2D18
PIPER COMANCHE SERVICE MANUAL