Chevrolet 10 Series 1970 Service Manual page 415

Maintenance and A d ju stm e n ts............................................................... 6Y-23
Periodic M a in te n a n c e ....................................................................... ... 6Y-23
Spark P l u g s ................................................... .................................... 6Y-23
C a b le s ............................................................................................. ... 6Y-23
G o v e r n o r ......................................................................................... ... 6Y-23
Service O p e ra tio n s................................................................................ ... 6Y-24
Distributor Contact P o in t s .............................................................. ... 6Y-24
Cleaning ......................................................................................... ... 6Y-24
R e p la c e m e n t.................................................................................. ... 6Y-24
Setting Dw ell A n g l e ....................................................................... ... 6Y-26
Distributor Condenser ..................................................................... ... 6Y-27
Perform ance Diagnosis ....................................................................6Y-27
PERIODIC M AINTENA N C E
The distributor break er points and spark plugs a re the
only ignition system components that req u ire periodic
s e r v ic e . The rem ainder o f the ignition system requ ires
only p erio d ic inspection to check operation o f the units,
tightness o f the e le c tric a l connections, and condition of
the w irin g. When checking the co il, test with a reputable
te s te r.
B rea k er type distributors a re equipped with cam lu b ri­
cator and should have the wick replaced at the same tim e
contact point set is replaced.
lubricate the break er cam when using a cam lubricator.
Do not attempt to lubricate the wick - Replace when
n ecessary. When installing a new wick, adjust its position
so the end o f the wick just touches the lobe o f the b reaker
cam.
D istributor shaft lubrication
r e s e r v o ir o f lube around the mainshaft in the distributor
body or through a hinge cap o ile r on govern or type units.
Spark Plugs
Should be rem oved, inspected cleaned and regapped at
tune-up. D efective plugs should be replaced.
Cables
The low and high tension cables should be examined
ca refu lly fo r b rittle o r cracked insulation and broken
strands. D efective insulation
cro s s firin g o f the engine. Connections should be clean
and tight.
Governor
Since governing speed is a function o f both the d is ­
tribu tor spinner and the carbu retor actuator, the only
p o sitive method o f accu rately setting 'speed is to adjust
the spinner on the veh icle.
throttle governing, road testing is n ecessary;
fo r p ra ctica l purposes it can be assumed full throttle
IGNITION SYSTEM S
Page
MAINTENANCE AND ADJUSTMENTS
It is not n ecessary to
is accom plished by a
w ill p erm it m issing or
F o r ex trem ely accurate full
however,
INDEX
R e p la c e m e n t..................................................................................
Distributor
Rem oval .........................................................................................
D isassem bly....................................................................................
Cleaning and Inspection
A s s e m b ly .........................................................................................
G overnor S e tt in g ...........................................................................
Installation ....................................................................................
Spark P lu g s ...........................................................................................
Cleaning and R e g a p p in g ..................................................................
In sta lla tio n .........................................................................................
Truck Engine Overspeed Warning .....................................................
F ig . l i —A d ju s tin g S pinner G ove rno r
governed speed w ill be about 200 rpm below no-load
governed speed. The adjustment can be made by " r e v -
ing" up the engine against the governor with the trans­
m ission in neutral.
The spinner mechanism can be adjusted by holding
the slotted end o f the valve with a screw d riv e r (fig. l i )
and turning the adjusting nut on the other end. Increase
the governing s p e e d
clockw ise, decrease
counter-clockw ise.
The governing system w ill operate s a tisfa cto rily fo r
long p eriod s if:
1. The vacuum passages
2. The governor a ir
enough to prevent re s tric tio n s to the supply o f clean
a ir necessary in operating the governing system .
ENGINE-ELECTRICAL 6Y-23
..............................................................
by turning the adjusting
t h e speed by turning
are kept fre e fro m
cleaner should be cleaned often
CHEVROLET TRUCK SERVICE MANUAL
6Y-27
6Y-27
6Y-27
6Y-28
6Y-29
6Y-30
6Y-31
6Y-33
6Y-33
6Y-33
6Y-33
nut
the nut
dirt.