Chevrolet 30 Series 1967 Service Manual page 368

ENGINE-ELECTRICAL 6Y-20
CABLES
The low and high tension cables should be examined
carefully for brittle or cracked insulation and broken
strands. Defective insulation will permit missing or
cross firing of the engine. Connections should be clean
and tight.
GOVERNOR
Since governing speed is a function of both the dis­
tributor spinner and the carburetor actuator, the only
positive method of accurately setting speed is to adjust
the spinner on the vehicle. For extremely accurate full
throttle governing, road testing is necessary; however,
for practical purposes it can be assumed full throttle
governed speed will be about
governed speed. The adjustment can be made by " rev­
DISTRIBUTOR C O N TA C T POINTS
CLEANING
Dirty contact points should be dressed with a few
strokes of a clean, fine-cut contact file. The file should
not be used for other metals and should not be allowed to
become greasy or dirty. Never use emery cloth to clean
contact points. Contact surfaces, after considerable use,
may not appear bright and smooth, but this is not neces-
CAM LUBRICATOR
BREAKER PLATE
ATTACHING SCREWS
F ig . 4 i—Breaker Plate and Attaching Parts
rpm below no-load
2 0 0
SERVICE OPERATIONS
CONTACT SET
ATTACHING
SCREW
QUICK
DISCONNECT
TERMINAL
ving" up the engine against the governor with the trans­
mission in neutral.
The spinner mechanism can be adjusted by holding
the slotted end of the valve with a screwdriver (fig.
and turning the adjusting nut on the other end. Increase
the governing speed by turning the
clockwise, decrease the
counterclockwise.
The governing system will operate satisfactorily for
long periods if:
1. The vacuum passages are kept free from dirt.
2. The governor air cleaner should be cleaned often
enough to prevent restrictions to the supply of clean
air necessary in operating the governing system.
3. Maintain tight cover bands or plugs on the dis­
tributor " spinner" compartment. Since a partial
vacuum exists in this chamber, dirt could be drawn
thru a leaking cover band and upset the operation of
the spinner valve.
sarily an indication that they are not functioning satis­
factorily. Do not attempt to remove all roughness nor
dress the point surfaces down smooth; merely remove
scale or dirt.
Badly burned or pitted contact points should be re­
placed and the cause of trouble determined so it can be
eliminated. High resistance or loose connections in the
condenser circuit, oil or foreign m aterials on the contact
surfaces, improper point adjustment or high voltages may
cause oxidized contact points. Check for these conditions
where burned contacts are experienced.
balance condition in the ignition system, often the result
of too much or too little condenser capacity, is indicated
where point pitting is encountered.
REPLACEMENT
Four and Six Cylinder Engine Distributor
1. Release distributor cap hold-down screws, remove
cap and place it out of work area.
2. Remove rotor.
3. Pull primary and condenser lead wires from contact
point quick disconnect terminal (fig. 4i).
4. Remove contact set attaching screw, lift contact point
set from breaker plate.
5. Clean breaker plate of oil smudge and dirt.
. Place new contact point assembly in position on
6
breaker plate, install attaching screw.
CAUTION:
Carefully wipe protective film from
point set prior to installation.
NOTE:
Pilot on contact set must engage match­
ing hole in breaker plate.
7. Connect primary and condenser lead wires to quick
disconnect terminal on contact point set.
. Check and adjust points for proper alignment and
8
breaker arm spring tension (fig. 5i). Use an aligning
tool to bend stationary contact support if points need
alignment.
NOTE:
The contact point pressure must fall
3
adjusting nut
speed by turning the nut
An out-of­
CHEVROLET TRUCK SERVICE M ANUAL
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