Piper Navajo PA-31 Service Manual page 948

PIPER NAVAJO SERVICE MANUAL
8. Place a new rope gasket (18) in position on the exhaust outlet, spring the jacket assembly
(17) open at the seam and insert the combustion tube assembly (19) carefully into the jacket. Exercise care
to clear the pressure switch tube in the exhaust outlet and see that the rope gasket (18) is properly located.
Close the gap on the jacket assembly and install screws (63) and lock washers (43) to secure it at the seam.
(Two leads ground under these screws. See notations made during disassembly.) Make sure the tongue and
channel at the seam are in good condition and a tight fit is effected.
9. Install cable straps at locations noted during disassembly.
10. If new spray nozzle is not being installed, remove the original nozzle (16) from the
polyethylene bag. Screw the nozzle into nozzle holder and tighten to 75-100 inch-pounds. It is very
important to torque the nozzle to this value as incorrect tightening could cause improper heater operation
and "drool."
CAUTION
The spray nozzle has a slight protrusion on the nozzle face. If this
area has been struck by any object which would make a dent or
destroy the original contour, the nozzle must be replaced. It
cannot be disassembled for cleaning.
11. Insert the fitting on end of nozzle fuel tube through the opening in jacket (17) and attach
the nozzle holder to the combustion tube assembly (19) with the two screws (61) and lock washers (62). It
may be necessary to place a slight bend in the shrouded fuel tube to permit alignment of screw holes. Be
sure to use a new gasket (15) and connect the solenoid ground wire under one of these screws. Make sure a
good electrical ground connection exists at this point.
12. Using a new spark plug gasket, install the spark plug (5) and tighten to a torque of 28
foot-pounds. Install the grommet (21) in the jacket around the spark plug.
13. Install the ignition assembly (3) on the jacket assembly (17) with the four screws (57) and
lock washers (58). Connect the high-voltage lead to the spark plug and tighten it to 20 foot-pounds.
14. Attach the radio-noise filter (6) to the jacket assembly (17) with the two screws (59) and
lock washers (58).
15. Attach the overheat limit switch (7) and spacer gaskets (8) to the jacket assembly (17) with
two screws (61), lock washers (58) and flat washers (65). Tighten the screws securely.
16. Attach the cycling switch (9) to the jacket assembly (17) with the two screws (61), lock
washers (43) and flat washers (65).
NOTE
After installing the overheat limit switch and cycling switch,
visually check to make sure that the switch does not come in
contact with combustion chamber. If necessary, add an additional
shim.
17. Place the terminal strip insulation (25) in position on the jacket (17), followed by the
terminal strip (10). Secure both parts by installing the two screws (64) and lock washers (58). The two
screws are located at two diagonal comers of the terminal strip.
18. Center the fuel fitting in jacket opening. Place the fuel fitting shroud gasket (26) and shroud
(14) on the fuel fitting and install the nut (60) finger tight. Insert a 3/4 inch open-end wrench inside the
jacket and hold the fuel-tube fitting while tightening the nut (60) with a 3/4 inch deep socket. Install the
bushing adapter (13).
Revised: 1/29/82
HEATING AND VENTILATING SYSTEM
5C18