Hercules JXD - Page 15

TM
9-1706
8-9
ORDNANCE MAINTENANCE
1
Symptom
Cause
h
.
Poor
gas
mileage
.
h
.
(
1
)
Worn
-
out
spark
plugs
.
(
2
)
Timing
late
.
(
3
)
Carburetor
dirty
and
out
of
adjustment
.
(
4
)
Motor
idles
too
fast
.
(
5
)
Brakes
dragging
.
(
6
)
Clutch
slips
.
(
7
)
Erratic
driving
.
(
8
)
Automatic
choke
out
of
ad
justment
.
( 9 ) Air
cleaner
dirty
or
too
full
of
oil
.
(
10
)
Automatic
heat
control
frozen
closed
.
i
.
Engine
fails
to
start
.
i
.
(
1
)
Fuel
system
clogged
or
fuel
supply
exhausted
.
(
2
)
Defective
fuel
pump
.
(
3
)
Air
vent
closed
.
( 4 ) No spark at spark plugs .
j .
Generator
fails to
charge
. j . ( 1 ) Drive belt loose .
( 2 ) Voltage
regulator
out
of
order
.
(
3
)
Generator
not
operating
properly
.
( 4 ) Poor connections in circuit .
k . Starting motion of vehicle k . ( 1 )
Worn clutch linkage
.
jerky or delayed .
( 2 ) Worn
or
oil
- saturated
clutch
parts
—
may
also
be
out
of
adjustment
.
( 3 ) Play in universal joints .
9. Tune - up . - a . General . - Best results are obtained in an engine
tune - up by using a systematic approach rather than a hit - or - miss
search .
Before
a tune - up is
attempted
an engine
compression
test
should be made .
Successful tuning
is
impossible without
a fairly even
compression in the cylinders . Make compression test in the following
manner :
( 1 ) Remove all spark plugs from the engine . Turn ignition switch
off and fully open hand throttle .
8