GMC 1976 ZEO 6083 Maintenance Manual page 704

Any change in the sensitivity adjustment usually
requires a compensating speed (spring tension) ad-
justment .
GOVERNOR BALL JOINT
Every 200 hours or sooner, check the governor
linkage for freedom of movement through its travel .
Clean and lubricate ball joint with lubricating graph-
ite.
ELECTRIC CHOKE
Manually check movement of choke travel to be
IGNITION AND BATTERY CHARGING SYSTEM
IGNITION TIMING BREAKER POINTS
To maintain maximum efficiency from the en-
gine, change the breaker points every 200 hours of
operation. Proceed as follows:
1 . Remove the two screws and the cover on the
breaker box.
2. Remove the two spark plugs so engine can be
easily rotated by hand . Check condition of spark
plugs at this time .
3 . Refer to Figure 39, remove mounting nut (A)
and pull the points out of the box just far enough so
screw (B) can be removed and leads disconnected .
4. Remove screw (C) and replace condenser with
a new one.
5. Replace points with a new set but do not com-
pletely tighten mounting nut (A).
6. Remove the dot button on blower housing.
This provides an access to view timing mark .
7. ON 4KW, rotate the engine clockwise (facing
flywheel) by hand until the 26° BTC mark on gear
cover aligns with mark on flywheel . Turn another
1/4 turn (90°) to ensure points are fully open .
On 6KW, rotate engine clockwise (facing fly-
wheel) By Hand Until the 20°BTC mark aligns with
hole . Turn another 1/4 turn (90°) to ensure points are
fully open .
8. Using a screwdriver inserted in notch (D) on
the right side of points, turn points until gap m
s
ures .025" (.016" on 6KW) with a flat thic
ss
gauge. (Be sure feeler is clean.) Tighten mounting
screw and recheck gap. Timing is automatically~set .
ONAN MOTOR GENERATOR 24C- 27
sure it is not stuck open or closed . Voltage at choke
should be 12 volts during start and drop to zero
during run. If choke does not move at room tempera-
ture with 12 volts applied, replace it .
This choke should not require any seasonal read-
justment . If adjustment becomes necessary proceed
as follows:
1 . Loosen choke lever clamp screw.
2. With lever fully forward (away from carbu-
retor), adjust so choke valve is completely closed or
not more than 1/4 inch open .
3. Tighten clamp screw.
The timing on the engine is preset at the factory.
A non-movable breaker point box is used, however
a slight timing change could be made by adjusting
points .
The engine is equipped with an automotive type
battery ignition system . Both spark plugs fire simul-
taneously, thus the need for a distributor is elimi
nated. Spark advance is set to specifications and
should be maintained for best engine performance.
Always check timing after replacing ignition points
or if noticing poor engine performance. Proceed as
follows :
TIMING PROCEDURE (ENGINE RUNNING
- HOT SETTING) (4KW)
1 . To check the ignition timing with unit running
use a timing light . Connect the timing light accord-
Figure 39-Breaker Point Adjustments