ignition
switch
first
to R position and note RPM. Next
move
switch
back
to BOTH to clear the other set of plugs. Then
move
switch to the L posi-
tion,
note RPM and
return
the switch to the BOTH position. RPM drop
should not
exceed
125 RPM on either
magneto
or
show
greater than 50
RPM differential between
magnetos.
If there is a doubt concerning
opera-
tion
of the ignition system, RPM
checks
at higher engine
speeds
will
usu-
ally
confirm whether a deficiency exists.
An
absence
of RPM drop may be an indication of faulty grounding of
one
side
of the ignition system or should be
cause
for suspicion
that
the
magneto
timir^
is set in
advance
of the setting specified.
ALTERNATOR
CHECK.
Prior
to flights where verification of proper alternator and voltage
regulator operation is essential
(such
as night or instrument flights), a
positive verification can be
made
by loading the electrical system momen-
tarily
(3 to 5
seconds)
with
the optional landing
light
(if so equipped), or
by operating the wing flaps during the engine runup (1700 RPM). The am-
meter
will
remain
within
a
needle
width
of
zero
if the alternator and vol-
tage
regulator are operating properly.
TAKE-OFF.
POWER
CHECK.
It
is important to
check
full-throttle
engine operation early in the
take-off run. Any
signs
of rough engine operation or sluggish engine
acceleration is
good
cause
for discontinuing the take-off. If this
occurs,
you are justified in making a thoroi^h
full-throttle,
static runup
before
another take-off is attempted. The engine should run smoothly and
turn
approximately
2270
to
2370
RPM
with
carburetor heat off and mixture
full
rich.
NOTE
Carburetor heat should not be
used
durii^
take-off
unless
it is absolutely
necessary
for obtaining smooth
engine acceleration.
Full-throttle
runups
over
loose
gravel are especially harmful to pro-
peller tips. When take-offs must be
made
over
a gravel surface, it is
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