Piper Cherokee Six - Page 378

PIPER
CHEROKEE
SIX
SERVICE
MANUAL
WARNING
When
performing
engine
warm-up
indoors,
provide
a
barrier
about
the
engine
to
prevent
serious
injury.
Also
provide
adequate
means
of
ventilating
the
work
area.
b.
Draw
back
on
the
cockpit
throttle
control
lever
to
obtain
a
reading
of
approximately
550
RPM
on
the
tachometer.
c.
Turn
the
idle
mixture
adjusting
screw
(1,
Figure
7-5),
located
near
the
rear
of
the
carburetor,
clockwise,
leaning
the
fuel
mixture.
Continue
to
do
this
until
the
engine
begins
to
run
roughly,
at
which
time
the
engine
speed
will
decrease.
d.
Turn
the
screw
counterclockwise
until
the
engine
runs
smoothly
again.
Continue
to
turn
the
screw
in
the
same
direction
until
the
engine
begins
to
run
roughly
once
more.
At
this
point
the
fuel
mixture
will
be
too
rich
and
engine
speed
will
decrease
again.
e.
Now
advance
the
screw
to
a
midway
position
between
the
lean
and
rich
fuel
mixture:
the
RPM
of
the
engine
will
reach
a
maximum
speed
for
idle
mixture
settings.
7-23.
ADJUSTMENT
OF
ENGINE
IDLING
SPEED.
a.
Pull
back
the
cockpit
throttle
control
lever
until
it
is
completely
aft
and
in
the
closed
position.
Observe
the
engine
speed
on
the
tachometer.
b.
Adjust
idle
adjustment
screw
(6,
Figure
7-5)
to
obtain
from
550
to
650
RPM.
Rotate
screw
clockwise
to
increase
the
speed
of
the
engine;
counterclockwise
to
decrease
engine
speed.
The
screw
is
located
on
the
throttle
arm.
NOTE
One
complete
revolution
of
the
carburetor
idle
screw
provides
a
variation
of
approximately
100
RPM
in
idling
speed.
POWER
PLANT
Issued: 8/17/72
2F6