Installation And Timing (Magneto To Engine) - Piper Dakota Maintenance Manual

8. Check capacitors for looseness in magneto cover and for any physical damage. Use a Bendix 11-1767-
1, -2, or -3 condenser tester or equivalent to check for capacitance, series resistance, and leakage.
Capacitance must be 0.34 to 0.4l microfarads.
9. Check magneto to engine timing.
l0. Check action of impulse coupling. With ignition switch off, observe breaker cam end of rotor while
manually cranking engine through a firing sequence. The rotor should alternately stop then (with an
audible snap) rotate rapidly through a retarded firing position. If impulse action is not correct, remove
magneto for overhaul.

INSTALLATION AND TIMING (MAGNETO TO ENGINE)

Do not attach harness spark plug ends to spark plugs until all
magneto to engine timing procedures and magneto to switch
connections are entirely completed.
1. Installation of magneto to engine is accomplished without removal of cover from magneto. Magneto
covers have switch terminal outlets for right and left side of magneto located in center of harness lead
outlet sections of cover.
2. The magneto incorporates a built-in pointer and a degree wheel with sufficient reference to assist in
magneto timing. Marks printed on the rotating magnet indicate magneto neutral and magneto E gap
(8°). (Refer to figure 74-5.) Retard angle references of 15, 20, and 25 degrees are included. These
marks are set up for either clockwise (R) or counterclockwise (L) rotation of magneto as viewed from
magneto drive end. The large distributor gear timing tooth is marked with red paint. (Refer to figure
74-6.)
3. When correctly timed, a magneto will have timing teeth of large distributor gears approximately
centered in timing windows, R or L (E gap) mark on rotor in alignment with pointer, and both main
breaker points opening, all at the same time. These three references are used when timing magneto to
engine.
4. Remove spark plug from No. l cylinder and turn crankshaft in direction of normal rotation until
compression stroke is reached.
5. Continue turning crankshaft until 23° advance timing mark is in alignment with small hole on top face
of starter housing at two o'clock position. (Refer to figure 74-3.)
6. Install magneto-to-engine gasket on magneto flange.
The use of a timing light unit Part No. 11-9110 or 11-9110-1 will
simplify the timing procedure. This unit is available from Bendix
Corporation at Sidney, New York 13838.
It is recommended that short adapter leads be fabricated to
facilitate connecting the timing light unit to the switch outlet
terminals of the cover. (Refer to figure 74 -4)
PIPER AIRCRAFT
PA-28-236
MAINTENANCE MANUAL
—WARNING—
—NOTE—
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2J1
74 - 11 - 00
Page - 74-05
Reissued: August 1, 1986