Piper PA-24 Comanche Service Manual page 465

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PIPeR COMANCHE SERVICE MANUAL
7C-51.
R.mO¥ll1 Of
Mapero. Before rernoviq the
mqnftO.
make sure mapcto switches
a.re
off.
&.
Remove the harness assembly tmniDal plate from the mqncto.
WARNING
The mapctO is not iDccma1ly JI01IDtied; wheD the pound lead is
discouectat.
the mapeto is hot. RcmOYinl me
hamal
wembly
termiD&l
plat.
tim and
jnn,m,.
it I.aa millimiza the
dafta'er
of
startiDI
the enpne accidcDtally when the pound lad is ranowd from the
mapcto.
b. Disconnect the poud
1ead
IIld the retard spark lead on the left mqncto. at the rn.qncto.
c.
Remove the nuts and wubcrs &Dd draw the mqactO from the entine.
7C·52.
TimiD,
Procedure. (Intemal TimiD,.)
a. Remove the cover to the c:oncaa(s). clistributor
block.
etc.
b. To internally time the main CODtact assembly of either the dual-breaker rnqnetos or the
si,.le-brc&ker
mapctot.
proceed u follows:
1. LoOllD the nut scc:uriq the drive place to the mapeto
shah
sufficieDuy in order to install the
Sc:iDtilla 11-3465 Rotor Holdiq Tool uDder the DUt and fiat washer
u
shown in
Fipre 7C-IO. Tighten the
nut securely.
2. Remove the
timiDI
inspectiOD plul from the top of the
mqDctO.
Tum rotating mqnet to
proper neutral position. This pOsitiOD is determined by locatitll keyways on drive end of magnet shaft at 12
o'clock with
respect
to
name
plate on bousq. Tichtcn &djustint knob of 11-3465 Rotor Holdi,. Tool
until pressure is applied OD bousiD. flaqe preventiq mapct from tumin,.
3.
Looscn aDd rotate cam. until cam
follower of main contact uscmbly rests on lliJhcst point of
cam
lobe. Adjust
main
contact uaembly to obtain the c:laraDce of 0.016
inch.
Ti,hten m&Ul contact
assembly securin. saews to 20-25
i.nc:.b
pounds.
4. Install the 11-3693 Timiq Plate A_mbly
and
the 11-3149 POUlter Assembly of the 11-3150
Sc:intilla Timq Kie to breaker compartment of
mapeto.
(Refer to Figure 7C·1l.) Align pointer assembly
With the
0
marlc
on timiq plate. LoolCll adjusting knob of 11-8465 Roeor Holdq Tool sad tum routing
mqnet in normal 4irection of rotation until pointer indexes with the respective E lap mark (1
S~ ~
t' ).
Tighten adjustialltnob of 11-3465 Tool and remove the 11-8149 Pointer Assembly from tnalfteto. t.:sing a
timing licht. adjust main contact points to just open. This adjusanent shall be made by rotating
C111\.
in
opposite direction of rotation. a few dqrees beyond poine where contactS close. Then rotate cam in normal
direction of roution until CODUetS just open. While holdin.
cam
in this exact position. push cam on
rDafllct
shaft
II
far
as
pomble with the
fmlftS.
Extreme
care must be exercised in this operation. If earn
adjustment
is chanp in the slilhtest dqree. the timinl of the mapeto will be thrown off. Do not drive
cam
on shaft
W1th a mallet or other in'tr\lmcnt. TiJbtcn the securiDi screw thereby dnwing the
cam
down. evenly and
tlght.ly. Torque
screw
to 16·20 inch pounds. Loosen the
11-346S
Rotor Holdinl Tool adjusting knob and
return rotatin. mqnet to neutral position. Reinstall the 11-8149 Pointer Assembly over 0
0
mark on timing
plate. Rotate mTet shaft in normal direction of rOtanOD and check for openinf of main o:ontact points at
E
gap setting
(1
S
=
~
). .
POWER PLANT
ISSUED: 8/18/72
2
H13