Piper COMANCHE PA-24-180 Service Manual page 419

PIPER COMANCHE SERVICE MANUAL
NOTE
No attempt should be made to stone or dress contact points Should
contact assembly have bad points or show excessive wear. the
complete contact assembly should be replaced.
e
Check the condition of the cam follower felt. Squeeze felt tightly between thumb and forefinger.
If fingers are not moistened with oil. re-oil using 2 or 3 drops of Scintilla 10-86527 lubricant Allow approxi-
mately 30 minutes for felt to absorb the oil Blot off the excess with a clean cloth. Too much oil may foul
contact points and cause excessive burning
7B-39. Removal Of Magneto.
a.
Loosen fasteners and lift the cowling side panel
b.
Disconnect high tension leads (short center lead) from the transformer
c.
Remove the four screws securing the harness block to the magneto and remove block
d
Disconnect "P~ lead from magneto and retard lead if removing left magneto
e Remove nuts and clamps securing magneto to engine and remove magneto
7B-40 Adjustment Of Magneto Breaker Points. If it is certain that the cam has not been moved since
manufacture or overhaul, the contact assembly points can be ad usted by setting them at 0019 inch (magnetos
S N 0627 and up are adjusted to 0 016 0 002 clearance on the high point of any cam lobe
If the cam has been disturbed or if it is not known that cam has been moved. time magneto using the
following procedure
NOTE
Magnetos of late manufacture have a brown strip of glyptal painted
across the cam retaining nut and the cam flange which makes it
possible to determine if the cam has been disturbed since manu-
facture or overhaul
a
The S700 magneto has raised timing marks as shown in Figure 7B-8. The center timing mark is the
reference or beginning point for proper timing and represents the full register position of the rotating magnet.
The "R" and "L" identify the two additional marks to be used for timing either a right-hand or left-hand
rotating magneto The first mark. in the desired direction of rotation. identifies the 27° past full register
instant of main contact assembly opening The second mark. 7-1 2° later. identifies the instant of retard
contact assembly opening on retard contact assembly magnetos
b
Loosen cam securing nut and run nut up flush with end of shaft. Loosen nut on drive end of rotor
shaft Remove main and retard contact assemblies and capacitor from breaker support assembly Rework a
plain washer as shown in Figure 7B-9 Slide inside diameter of washer against rotor shaft between cam and
breaker support assembly Tighten nut on drixe end of magneto until cam is loose on rotor shaft Remove
reworked washer from housing.
ISSFlED: 8/18/72 POWER PLANT
2F13