Piper Navajo PA-31 Service Manual page 461

PIPER NAVAJO SERVICE MANUAL
8-2. TROUBLESHOOTING. Troubles peculiar to the power plant are listed in Table VIII-II in the back of this
section, along with their probable causes and suggested remedies. The cable is divided into two parts, engine
and turbocharger. When troubleshooting engines, ground the magneto primary circuit before performing any
checks on the ignition system.
8-3. ENGINE COWLING.
84. REMOVAL OF ENGINE COWLING. (Refer to Figure 8-1.) The procedure for removing the cowling is
the same for either engine.
a. Release the fasteners (6 and 8) that attach the two cowl halves (1 and 2).
b. To remove the cowl half (2), disconnect the cowl flap control rods (11) from the flap (3), support the
cowl and release the screw fasteners (9) that secure the aft section to the nacelle.
c. The upper half may be removed by releasing the screw fasteners (7) that secure the aft section to the
nacelle.
CAUTION
Ground running with the cowling removed, maximum power
ground running is limited to two (2) minutes or cylinder head
temperature of 45()
°
F, whichever is reached first. Prolonged
ground running with the cowling removed could cause local hot
spots in the cylinders and irreversible engine damage.
8-5. CLEANING, INSPECTION AND REPAIR.
a. The cowling should be cleaned with a suitable solvent and then wiped with a clean cloth.
b. Inspect the cowling for dents, cracks, loose rivets, damaged or missing fasteners and damaged fiberglass
areas.
c. Check flange on forward baffle for .38 clearance between baffle and cowling, flange may have to be
bent forward.
d. Repair all defects to prevent further damage. Fiberglass repair procedures may be accomplished according
to: Fiberglass Repairs, Section IV.
8-6. INSTALLATION OF ENGINE COWLING. (Refer to Figure 8-1.) The procedure for installing the cowl is
the same for either engine.
a. Position the upper cowl half (1) and secure with screw fasteners (7) along the aft section of the cowl.
WARNING
The cowling fastener locked position stripe must me maintained.
Refurbish or replace stripe if faded, missing or cowling is
repainted.
b. Raise the lower half (2) to join the upper half, secure the screw fasteners (9) along the aft section of the
cowl and lock the fasteners (6 and 8) that join the two halves. Fasteners (6), 3 per side on each cowl, and 8)
have a dark line painted along the top half of the fastener and cowling. This is done so a visual check can distin-
guish when the fasteners are open or closed. In addition to the paint stripe, each fastener (6) has a pin in the
center of the screw slot that will protrude into the slot, if properly locked, when screw driver is removed
Revised: 2/18/94
POWER PLANT
2H11