Onan MDJF Series User Manual

ADJUSTMENTS
CHECK CENTRIFUGAL BREAKER POINTS
Refer to Dimensions and Clearances for correct gap dis-
tances. Replace burned or faulty points.
If only sligjitly burned, dress smooth with file or fine stone.
Measure gap with thickness gauge (Figure 16).
The centrifugal switch is wide open when engine is stopped.
Loosen and move stationary contact to correct gap.
NOTE: Rotate engine cranks&alt a few degrees counter-
clockwise before adjusting points. To release any torsional
forces created by the water pump impeller. Use a socket
wrench on the flywheel retaining screw.
GOVERNOR
The governor controls engine speed. Rated speed and volt-
age appear on the nameplate (see also Specifications).
Engine speed equals frequency multiplied by 30 on a 4 pole
generator, thus ISOOrpm is 60hertz.. The speed should
not vary, more than 3 hertz from no load to full-load oper-
ation. Be sure throttle, linkage and governor mechanism
operate smoothly.
governor is too sensitive, a rapid hunting condition occurs
(alternate increasing and decreasing speed). Adjust for
maximum sensitivity without hunting. After sensitivity ad-
justment, the speed will require readjustment. After adjust-
ing the governor, secure lock nut.
IMPORTANT: Excessive droop may be caused by engine
misfiring. Correct this condition before adjusting governor.
VALVE CLEARANCE
Check valve clearance when the engine is at room tempera-
ture (about 70° F).
Speed Adjustment: To change the governor speed, change
the spring tension by turning the governor spring nut (Figure
18). Turn the nut clockwise (more spring tension) to increase
RPM and counterclockwise to reduce governed speed. Hold
a tachometer against flywheel cap screw or use frequency
meter.
Sensitivity Adjustment: To adjust governor sensitivity
(no-load to full-load speed droop), turn the sensitivity ad-
justing ratchet (Figure 18). Counterclockwise gives more
sensitivity (less speed drop when full load is applied),
clockwise gives less sensitivity (more speed drop). If the
CENTRIFUGAL
SWITCH
BREAKER POINTS
SET GAP AT
.040"
1. Turn the flywheel until the cylinder which is to have
its valve adjusted is on its compression stroke. Use a
socket wrench on the flywheel screw hex head.
To determine if the cylinder is in its compression
stroke, observe the action of the push rods as the
engine is rotated in a clockwise direction. The exhaust
• valve push rod will be in its lowest position and the
intake valve push rod will be moving downward. As the
piston reaches top dead center, the flywheel timing
mark should be aligned with the timing pointer and the
valve push rods stationary.
A883 .
MAXIMUM STOP
FIGURE 16. CENTRIFUGAL SWITCH
FIGURE 17. SETTING STOP SCREW
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Onan MDJF Series Specifications

General

Brand	Onan
Model	MDJF Series
Category	Inverter
Language	English