Chevrolet 10 Series 1970 Service Manual page 425

F ig . 20 i —E ight C y lin d e r Engine D is trib u to r
NOTE: The brackets a re numbered to show the
c o rre c t installation. W ire s must be installed as
indicated to preven t cro s s firin g .
8. Connect vacuum line to distribu tor and distributor
p rim a ry w ire to coil term in al.
9. Start engine and set
Tune-Up in Section 6.
SPARK PLUGS
Cleaning and Regapping
Clean the spark plugs thoroughly, using an a b ra sive -
tim ing as d escribed under
F ig . 2 l i —S e ttin g Spark Plug G ap
type clean er. If the p orcela in s a re badly gla zed or
b lis te re d , the spark plugs should be replaced. A ll spark
plugs must be o f the same make and number or heat
range. Use a round fe e le r gauge to adjust the spark plugs
gaps to specification s (fig. 2l i ) .
CAUTIO N: B efo re adjusting
electrode flat. In adjusting the spark plug gap,
never bend the center electrode which extends
porcelain
through the
adjustment by b e n d i n g
electrod e.
Installation
Install the spark plugs in the engine with new gaskets
and torque to sp ecification s.
ava ilab le, tighten plugs fin ger tight and 1/2 turn m ore.
Plu gs a re o f a 14 m illim e te r size and care must be e x e r ­
cised when installing or the gap setting may be changed.
TRUCK ENGINE OVERSPEED W A R N IN G SYSTEM
The purpose of this overspeed warning system is to
warn the d riv e r o f ex ce s s iv e engine speed in an o ver-ru n
condition (such as during down hill operation when the
w heels may begin to d riv e the engine) and thus enable
steps to be taken to c o rre c t the condition.
The system (fig. 22i) consists o f an am ber jew eled
warning lamp mounted in the cab, a vacuum sensing
switch in the spinner govern or vacuum line, and a w arn­
ing lamp burnout checking circu it.
operate in conjunction with
(Vacuum Spinner T yp e) d escribed in Section 6M o f this
Shop Manual.
In operation, when the engine reaches its governed
speed (4000 rpm with standard transm ission o r with
ENGINE-ELECTRICAL 6Y-33
gap, file center
m a k e
center. A lw ays
the ground or side
If torque wrench is not
These components
the 2G Engine G overnor
CHEVROLET TRUCK SERVICE MANUAL