PIPER
COMANCHE
SERVICE
MANUAL
7B-50_
ilupec:tion
ADd
Clanin,
Of
Sport. Plul_
._
Visually inspect eadt spark
plul
for the followiDs aon-repaiftbk defec:a,
L Severely d.unq<d
sheU
or
shield threads nicked up. Stripped
or
aoathreaded.
Z.
Badly battered or rounded
sheU
""""IOns.
3.
Out-of-round
Ot
damaged shieldinJ barrel.
4.
Chipped.
encked.
or
broken
ceramic insulator portions.
5.
Badly eroded electrodes worn to &l'proximately
,oq(,
of
oriJiaal
size_
b. Clean the spark
plu,
..
required.
removing
carbon and for
....
doposia.
c. Test me spark
pi",
both elec:u-icalJy and for
raiswlce.
d. Set the electrode
'&I'
at
.015 ro .018
of
UI
iach
or
ii
& smoother operation
at
idle speed and
reduced magneto
dro~ff
is
desired.
Set
at
.018
to
.022
of
an iacb. However. with wide
'&I'
settins
the
plup
must be serviced at more frequent iamvals. Fiae wire platinum
or
iridium elec:uodes should be
Set
at
.015
to
.018
of
an inch ollly.
7B-51.
I.....u.tion
Of
Spck'
...
Before insalling spark plugs. ucett2in
that
the threads within
the
cylinder are
dean
and not
da.mo...
...
cQ..
..
Apply
anti...ue
compound
spuingly
on the
threw
&ad
install
psket
and spark
plup.
Torque 360
to
~20
inch pounds.
CAUTION
M&i<e
ceruin
the deep socket is properly seated
on
the spark
pi",
hexqon
..
damage
to
the
plug could result
ii
the wrench
is
cocked to
one
side when pressure is applied.
b.
CuefuUy insert the tenninal insulator
in
the spark plug and
tilhtcn
the
co~pling
nut.
7B-52.
Lubrication System.
7B-53. Oil
Relief Val
...
The function
of
the oil pressure relief
valve.
which
IS
located between the
upper
nght
engine mounting
lug
&ad
No.7
cylinder. IS to maintain engine oil pressure within specified limlt5 by
withdrawing
il
portion
of
the oil from the circulatina system and returning the oil to the sump should the
pressure become excessive. Tbis valve
is
noc adjuStable, however, panicles of metal
or
other forclll'
matter
lodged berween ball .rid
..
at
will result in • drop
in
oil pressure. It
is
advisable. merefore. to disassemble.
inspect
and
clean
the
relicf vah'c
if
excCSSlvc
pressure fluctuations are noted.
The oil
pressure relief
valve
is
by no means to
be
confused with the oil cooler by·pass valve. whIch is
located on
the:
au.
pressure screen housing mountmg pad. The sole purpose of the by·pass
valve
:s
to serve
a.s
a safety measure. pemutnns: pressure oil to by-pass the oil cooler enarely
in
case
of
an obstTUcnon withm
the cooler
POWER
PLANT
ISSUED:
8/18172
2F23
To Next Page
Loading...
Need help?
General
