Piper COMANCHE PA-24-180 Service Manual page 382

FIGURE 7A-21. ENGINE TIMING MARKS
g. Turn on the timing light switch.
b. Rotate the magneto housing m the direction of the magnet rortion
x
few degrees until the timing
light comes on. Then slowly urn magneo in opposire direction until the nming light goes ouc. Secure the
magneto housing
in
this position.
NOTE
Some timing lights operate the opposite ot the one mentoned.
PIPER COMANCHE SERVICE MANUAL
m
i.
Rotate the crankshaft opposite normal rotation until i is approximately 35 degrees BTC on
compression stroke No. one cylinder.
NOTE
The crankshaft should nor be rotated more than 10 degrees in directon
opposite normal rotation from the 25 degree BTC as the pawl on the
impulse coupling (-21 magnetos) will engage with the stop pin and late
trimng will be indicated through the impulse coupling mechanism. If this
should happen, rotate crankshaft in normal direction unil sharp click is
heard; this will indicate rhar the impulse coupling has passed through
firng position. Turn crankshaft in direction opposte normal rotation to
approximately 35 degrees BTC and proceed with tming check.
POWER PLANT
REVISED: 4/10/81
0
2 D24