Governor And Carburetor Adjustments - Onan BGM Series Service Manual

GOVERNOR AND CARBURETOR
ADJUSTMENTS
The governor operates the throttle to maintain a
nearly constant engine speed (frequency) as the
electrical load on the genset varies. Careful adjust-
ments of the carburetor and governor are essential
for top performance. Perform all necessary engine
and generator maintenance and repairs before
making these adjustments.
Governor and carburetor adjustments should be
done together. They require the use of meters to
measure voltage, frequency and amperage and a
.stepped load bank of at least 8 kW, where a portion
of at least 600 watts is variable. Digital meters are
recommended. Accuracy should be at least 0.3 per-
cent for frequency measurement and 0.5 percent
for voltage measurement.
Beginning Spec F, carburetor fuel mixture adjust-
ing screws are not accessible. Other than turning
the altitude adjust knob to compensate for altitude
on gasoline carburetors, fuel mixture adjustments
should not be attempted.
IAWARNINGI
Unauthorized modifications or re-
placement of fuel, exhaust, air intake or speed
control system components that affect engine
emissions are prohibited by law in the State of
California.
IAWARNINGI
Disconnect or unplug all voltage
and frequency sensitive devices such as TVs,
ACTUATOR
LEVER
GOVERNOR
ACTUATOR
/
GOVERNOR
ROD
VCRs, computers and other solid-state elec-
tronic devices before making governor and car-
buretor adjustments. Typically, some internal
circuits are powered when these types of de-
vices are plugged in, even if the device has been
switched "OFF". These circuits can be dam-
aged by variations in voltage and frequency that
occur during these tests.
Electronic Governor
Electronic governor speed and sensitivity set points
are not adjustable. The governor actuator and link-
age (Figure 6-1 0) are accessible by removing the
top panel. The governor controller is mounted on
the base pan (Figure 7-5).
Disconnecting the Governor Rod: Remove the
top panel (see COOLING SYSTEM in this section)
for access to the governor rod. Unhook the gover-
nor rod and spring from the governor actuator arm
first. Use both hands so as not to bend the actuator
arm. Then unhook the rod and spring from the
throttle.
Reconnecting the Governor Rod: Before recon-
necting the governor rod check to see the the paint
seal on the throttle stop screw on the carburetor has
not been broken. If it has been broken, readjust the
throttle stop screw as follows:
1. Disconnect the governor rod from the actuator
arm if it has not already been removed.
1
SPRING
FIGURE 6-10. ELECTRONIC GOVERNOR UNKAGE
6-14