Piper PA-24 Comanche Service Manual page 415

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PIPER CO)1A:\CHE
SI~R\'ICE
\1A:\L\l
\OTE
l hc id
lc mixture must he
adiu-tcd with
the fuel
boo-t
pump
"0'."
d. \\ hen the idling
"p~~d
has been -tabilized. move the cockpit mixture control with a smooth. <teadv
pull toward the "Idle Cut-Off" position and observe the tachometer for any change during the "leaning
process. Caution must be exercised to return the mixture control to the "Full Rich" position before the R P\l
ca ,. d rop to a poin t \\ hen: the engi ne cuts out. An increase of more t ha n SO R P\1 \\ hile "It:aning out" indica te-
an
t:_\.c.:""i\el~
rich idle mixture..-\n immediate decrease in RP\l (if not preceded
b~
a mornentarv increa-ct
indicates the idle mixture is too lean.
e. If the above indicates that the idle adjustment is too rich or too lean. turn the idle mixture adjust-
ment in the direction required for correction. and check this new position
h~
repeating the above procedure.
Make additional adjustments as necessary. Each time the adjustment i" changed. the engine should he run up
to 2000 R P\1 to clear the engine before proceeding with the RP\I check. Make final adjustment of the: idle
-peed adiu . . . trncnt
1\)
obtain the de. . . ired idling RP\-t with closed throttle. The above method aim ... at a cuing
that will obtain maximum RP\1 \\ ith minimum manifold pres ure. In case the setting dot:. . . not remain table.
check
t
he idle linkage:
an~
loo-ene . . . s in thi . . . linkage would cau e erratic idling. In all ca...es. allowance hould
he made for the effect l)f weather condition... and field altitude upon idling adjustment.
7B-~). Fuel Air Bleed :\ozzles.
-8·~4.
Removal Of Fuel Air Bleed
~ozzles.
r
Rcfer to Figure '8·7.) The nozzle . . . mu...t he
curctullv removed
a"
thc~
or the
.:~
linder... may he damaged.
a. lilt
t
he "ide access panels of the engine
':0\\
ling.
h. Di. . . connect the fuel line from the nozzle.
c.
Curctullv remove
the novzle. u. . . ing the correct
xize
deep . . . ocket.
d. Clean and inspect the novzlc as given in Paragraph 78-.1S.
-R-_'5.
Cleaning And Inspection Of Fuel Air Bleed
~oZlleo;.
a Clean the nozzle, with acetone or Mcthylerhylkctonc (\1 EK Iand blow out all foreign panicle" \\ ith
compte.....cd
air
in the direction opposite that of fuel flow. Do not use \\ ire or other hard o hiect-,
h)
clean
ori
I
ice
v.
h. In. . . pect the nozzle and cylinder threads for nick.......tripping or cro-,. . . -thrcuding and battered or
r0unded he'agon ....
c.
lnvpcct
and replace nozzle Ovnngs found to be cracked. brittle or distorted. Refer
to
l~
corning
Sen ice Instr uction . . .
'0.
12"'S
for detailed te-a procedure of air bleed nl)/lIe.;.
-R-~fl.
Installation
or
Fuel Air Bleed
~ozlle.
a. It i... important for the nozzles to be correctly po... itioned with the air bleed hole facing upward.
b. In..tall the nOllles and tighten to a little le. . . s than flO inch-pounds torque.
c. Continue
to
tighten the nozzle ... until the letter or number ...tamped on the hex of the nOIl!c
hod~
point-
Jtl\\
n. In this position the air bleed hole \\ ill face upward.
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ISS CEO:
8/114(72
2F11
POWER P1.A'T