Timing Marks On Magneto Rotor - Piper PA-44-180 SEMINOLE Maintenance Manual

7. Remove the magneto drive gear backlash by turning the propeller opposite to normal rotation approximately
40° past the No. 1 firing position. Then turn the propeller in the direction of normal rotation up to the No. 1
firing position of 23° BTC.
8. Remove the timing window plug from the most convenient side of the magneto housing. Also, remove the
plug from the rotor viewing window in the center of the housing.
9. Turn the rotating magnet drive shaft in the normal direction of magneto rotation until the red distributor
tooth is centered in the timing hole. Also, check to ensure that the built-in pointer just ahead of the rotor
viewing window aligns with the R or L mark on the rotor depending on whether the magneto is for right or
left-hand rotation as specified by the magneto data plate.
10. While holding the magneto in its No. 1 firing position (tooth in window center and pointer over R or L mark
on rotor), install the magneto to the engine and loosely clamp in position.
Engine should be in No. 1 cylinder firing position of 23° BTDC.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
20°
15°
Figure 74-5. Timing Marks on Magneto Rotor
— Note —
3F24
RETARD ANGLES
25°
8°
"E" GAP ANGLES
8°
7 4 - 11 - 0 2
Page 74-07
Revised: May 15, 1989