Service manual

For
I
521TU
PL521TN
MAINTENANCE
INTERVAL
ENGINE
SERVICE
POINTS
0
6
3
6
g
12
15
18
21
24
27
30
Number
of
months
or
thousands
of
miles
whichever
33
36
39
42
45
48
51
comes
first
54
57
60
Replace
c
bureter
air
cleaner
element
X
Check
or
lace
spark
plugs
X
X
X
R
X
X
X
R
X
X
R
Check
or
lace
distributor
breaker
points
X
X
X
R
X
X
X
R
X
X
R
Replace
0
filter
X
X
X
X
X
X
X
Replace
c
ridge
type
fuel
strainer
X
Retighten
IInder
head
bolts
and
manifold
nuts
X
Adjust
val
clearance
X
X
X
X
X
X
X
Check
an
djust
ignition
timing
X
X
X
X
X
X
X
X
X
X
X
X
Check
hig
tension
cables
X
X
X
Check
fan
elt
tension
X
X
X
X
X
X
X
AdjuSl
en
e
idling
X
X
X
X
X
X
X
X
X
X
X
X
Engine
tu
up
X
X
X
Check
fue
ine
hoses
pipings
connections
etc
for
leaks
X
X
X
X
X
X
X
X
X
X
X
X
Check
en
e
for
oil
and
water
leaks
X
X
X
X
X
X
X
Check
ba
ry
specific
gravity
X
X
X
X
Check
air
mp
belt
tension
X
X
X
X
X
X
X
X
X
X
X
X
Check
ho
piping
conneclions
for
loose
A
I
S
P
C
V
I
X
X
X
Check
air
mp
for
operation
X
X
X
Check
em
ion
control
valves
for
oper
tion
X
X
X
Check
fa
peratio
of
electrical
5witt
es
of
emission
control
system
X
X
X
R
Replacement
r
C I
C I C I