During gaseous fuel operation, the choke is locked
in
the full open position by the choke lock wire, Figure
18.
..
1\
. ONAN THERMO-MAGNETIC CHOKE
This choke uses a heating element and a heat
sensitive bimetal spring
toopen
the choke. The choke
solenoid, actuated
durillgengine
crankihg only,
closes the choke according
to
ambient temperature.
If adjustment is required, use the following instruc-
tions. Choke bimetal spring must be at ambient
temperature. Allow engine
to
cool at least one hour
before setting. Adjust choke by turning the choke
body, which engages a link connected to a bimetal
choke spring. Remove air cleaner and adapter to
expose the carbu retor th roat. Loosen the screw which
Secutes the choke body. Rotate choke body
clockwise
to
inc rease choke
and
cou nterclockwise to
decrease choke action (leaner mixture). Refer to
Figure
19
for
correct choke setting according to
ambient temperatu
reo
Use d rill rod
or
shan k of d rill bit
to measure choke opening.
GOVERNOR
The governor controls engine speed. Rated speed
and voltage appear on the nameplate (see also
Specifications). Engine speed equals frequency mul-
tiplied by30, on
a4
pole generator, thus 1800 rpm give
r
60
hertz frequency. Preferred speed does
not
vary
,\
more than 3 hertz from no-load to full-load operation.
Be
sure throttle, linkage, and governor mechanism
operate smoothly.
Speed Adjustment:
To
change the governor speed,
change the spring tension by turning the governor
spring nut (Figure 20). Turn the nut clockwise (more
spring
tension)
to
increase
RPM
and
counterclockwise to reduce governed speed. Hold a
tachometer
against flywheel cap screw.
SensUMtyAdJustment: To adjust governor sensitivity .
(no load to full load speed droop) tu
rn
the sensitivity
adjusting ratchet accessible through a covered
access hole on the side
of
the blower housing.
Counterclockwise gives more sensitivity (less speed
drop
when full load is applied), clockwise gives less
sensitivity (more speed drop). If the governor
is
too
sensitive, a rapid hunting condition occurs (alternate
inqreasing and decreasing speed). Adjust
for
max-
imum sensitivity without hunting. After sensitivity
adjustment, thespeed will require readjustment. After
adjusting the governor, replace the knockout
p.lug
in
the blower housing and secure speedstud lock nut.
Excesslye
droop
may be caused
by
engIne misfiring. Correct this
condlUon before aeQustlng goyemor.
CHARGE RATE ADJUSTMENT
The adjustable resistor slide tap (in the charging
circuit) is
setto
give approximately 2 ampere charg-
ing rate. For applications requiring frequent starts,
check battery specific gravity
periodically and,
j·f
necessary, increase the charging rate slightly (move
slide tap nearer ungrounded lead) until it keeps the
battery charged. Adjust only when engine is stopped.
Avoid overcharging. The resistor is located in the
generator air outlet.
If a separate automatic demand control
for
starting
and stopping is used, adjust the charge rate
for
its
maximum 4:5 amperes. This normally keeps battery
charged even
if
starts
occur
as
often
as
15 minutes
apart.
SPEED
TURN
TO
INCREASE RPM
ADJ USTING
NUT
(Hold
Spring
Stud
in
.
Position)
(Sens
icivity
Adjustment)
GOVERNOR
ARM
.
SENSITIVITY
ADJUSTING
RATCHET
FIGURE
20.
GOVERNOR ADJUSTMENT
19
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