Magneto Breaker Points Adjustment - Piper PA-24 Comanche Service Manual

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P'PER
COMA~CHE
SERVICE :\'lASt: L
'0
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 Ioul
contact points and cause excessive burning.
78-39. 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.
"'8-40. Adjustment
Of
\1agneto Breaker Points.
If it is certain that the cam has not been moved
~IOCC
manufacture or
0\
erhaul, the contact assembly points can be adjusted by setting them at 0.0 19 inch
I
magneto-
S
'Of>:!-
and up are adjusted to 0.016
j;
o.oo:n
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
uxing
the
follow ing procedure:
'OTE
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
iB-R.
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
c
pa-t full register
instant
of rna in contact assembly opening. The second rna rk. 7-1 2° later. identifies the instant of reta rd
contact assembly opening on retard contact assembly magnetos.
h. Loosen cam securing nut and run nut up flush with end of shaft. Loosen nut on
drive
end nf rotor
...haft. Remove main and retard contact assemblies and capacitor (rom breaker support assembly. Rework a
(llain wa-her as shown in Figure
78-9. Slide inside diameter of washer against rotor shaft between cam and
breaker vupport assembly. Tighten nut on drive end of magneto until cam is loose on rotor
-hatt. Remove
J'I:\\
orkcd \\ asher from housi ng.
ISSl'ED: 8/18/72
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POWER PLA:'\T