Vibrator Checking Procedure - Piper PA-24 Comanche Service Manual

PIPER COMANCHE SERVice MANUAL
1.
TiJhtcn the two mountinl nuts and
replace
the iDJpection pi'll.
m. Afur tiahteniJla m&fJ'etO mounM, nuts check
timinJ
to
make
SUN
it is still
COlftet.
n. lnmll the other mapero and time
usint
the
Prccediat
inlmae:tiOIlS
A
tbroUJb
M.
o. With both ma,neros timed to the eqiDc and secured.
check thae they fIR eopcber. Rouee tbe
crankshatt opposite normal roution to appromnaeciy
35 depus
ITC with No. 1 cylinder
on the
compression moke.
p. If the maperos
ate
timed correctly. both
tiIniIIf
upa
will 10
OUt
silnulcancously when the
crankshaft
is
nuned in the norma! direction
&lipin,
che 15
de,ree
marks
with the
drilled
hole in the seaner
housan, or the
crankcase
pucinf
surfaces.
q.
DiscoMect
timiaJ
lisht.
Asccnain that theiaspection pIlip
aDd
braker
cover arc
insullcd and
secure.
r.
Inscall hamal
plate and
ICC1If'C
with
Krn/1.
s. Connect "P"
leads
and safety.
t.
Conneee sW'tint vibrator lead to the left -200 mapeto.
u.
Secure engine cowlinJ.
745. SCIttiDt
Vibrator
Checkial f'roadUft.
a. Measure voltaIC
between
vibrator tmninal
marked "in" and the pound terminal
while opera.ting
suna. OutpUt must be a.t lcut 8 vola on 12 volt
sysccms.
b. If volUle is adcqua.te.
listen
for bU%zm, of vibrator dunn,
R.IftiDJ.
If no buzzin, is heard. either
the vibra.tor
is
dcfectiw or the circuit from the outpUt
"SO" tcrminaJ.
on the vibrator to the
retard
(dual
breaker) mqneto is open. Check both switch a.nd
mard circuits. Also
check
for
JOOd
eleettica! ground.
c.
Retatd poina ma.y not be closing due to
WI'ODI
a.djUIUDCDt. or may be elccmca.lly cOMec:red in
the circuit due to
a
poor connection.
Inspect
retard poina to
ICC
if they
elOIe.
Check for proper contact a.t
the switch a.nd rcurd tcrmirlals of lewd (dual breaker)
ft'IaIJIcta and at
the
vibrator. Check witin,.
d. TW'ft enpne
in
proper di1'cction of rocation until
retard
poina jllSt open No.1 cylinder position.
Remove input connection
from
Rafter to ptne1lt " e
Nl'Ilm,.
On the
PA.-1~180. PA.·2~250
a.nd
P.~·2+-260
hold No. 1 pll1l
lead 5/16
inch
spark.
On me PA·24-400 check
spark
by removinl spark pluS.
connectiftl lead to plug a.nd Jl'Oundinr piUJ. OblCrVC spark at plul' spark cap.
If spark is wca.k or mislinr
try new vibrator.
If this docs not correct trouble tcmove JUlftCtO
and
cbeck for improper
intcma.l
rimiftl or
improperly meshed distributor
pan.
CAlJTION
When chew.. vibrator action. stand
dar
of propeller or
remove
spark
plug tmnina.1s.
POWER PLANT
ISSUED: 8/18/72
2
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