Hercules JXD - Page 14

TM 9–1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS
8
Symptom
e . Engine knocks .
f
.
Grinding
or
scraping
noise
in
engine
.
Cause
e
.
(
1
)
Carbon
deposit
in
head
.
(
2
)
Spark
advanced
too
far
.
(
3
)
Automatic
spark
advance
stuck
.
(
4
)
Governor
weights
stuck
or
springs
weak
.
(
5
)
Loose
wristpins
.
(
6
)
Connecting
rod
out
of
alinement
.
(
7
)
Loose
rod
bearings
.
(
8
)
Loose
main
bearings
.
(
9
)
End
play
in
cam
shaft
.
(
10
)
Loose
tappets
.
(
11
)
Sticky
valve
stems
.
(
12
)
Loose
spark
plugs
.
(
13
)
Flywheel
loose
.
f
.
( 1 )
Generator
bearings
worn
.
(
2
)
Water
pump
bearings
bad
.
(
3
)
Lower
fan
pulley
sprung
or
frame
sprung
so
trun
nion
hits
pulley
.
(
4
)
Broken
ring
or
piston
.
(
5
)
Flywheel
pan
bent
or
dirt
in
flywheel
pan
hitting
flywheel
.
( 6 ) Timing
chain
loose
and
rubbing
case
.
(
7
)
Oil
pan
nuts
in
flywheel
housing hitting against
flywheel .
q . ( 1 )
Piston ring gaps lined
up .
( 2 )
Piston rings worn
or
car
bon
in
ring
grooves
.
(
3
)
Vacuum
pump
diaphragm
cracked
or
porous
.
(
4
)
Rod
or
main
bearing
has
too much clearance .
( 5 ) Oil slinger clearance too
great
or
oil
slinger
oil
seal
in
housing
worn
out
.
(
6
)
Excessive
cylinder
wear
.
g
.
Engine
uses
too
much
oil
.
7