Table 14-2. Fuel Delivery
60-65 psi (hold)
(high idle) 918
(3) Start stand at lowest speed and check for
Move throttle to full-load posi-
tion. When transfer pump picks up suction, allow
fuel to bleed for several seconds from loosened con-
Likewise, allow fuel to bleed from
loosened injection line nuts. Tighten securely.
(4) Operate Pump at 500 rpm for 10 minutes.
Dry off completely with compressed air. Observe
for leaks and correct as necessary. Back out the
high idle stop screw and torque screw.
The inlet to the transfer pump should
never be pressurized during bench testing.
(5) Close valve in supply line -transfer pump
must pull at least 18 inches hg at 200 rpm.
If it does not, check for air leaks on suction side or
malfunction of end plate and transfer pump parts.
(6) Fill graduates to bleed air from test stand
and to wet glass.
(7) Observe return oil. Return should be at
rate of 100-450 cc/minute at 35 psi transfer pump
Under no circumstances should 130 psi be
exceeded, as the pump will be damaged.
(8) Operate at the 900 rpm with wide
open throttle and observe transfer pump pressure.
Adjust pressure-regulating spring plug to raise or
lower transfer pump pressure.
(9) Check for minimum delivery at crank-
ing speed of 75 rpm.
The delivery rate should
be a minimum of 65 mm3/s at a minimum of 8 psi.
(10) Operate at 918 rpm. and adjust high idle
screw to obtain 20-25 percent of full-load fuel
(11 ) Adjust the low idle screw, if used, to
a low idle delivery of 10-12 cc/1000 strokes at
(12) Check the cam position at specified points
in the speed range given in table 14-2. Attain all
speeds by first running at a higher rpm, then reduce
to normal operation speed. Adjust trimmer screw,
or shim, as required, to obtain proper advance
Each mark on the timing window is
14-54 Change 1
2 pump degrees (4 engine degrees).
(13) Record fuel delivery at check points shown
in table 14-2.
Roller settings should not be readjusted
on the test bench. Micrometer and dial
indicator settings provide more consis-
tent, accurate results in performance.
Variations in test benches, nozzles,
lines, and fuels in different areas some-
time result in inaccurate flow readings.
(14) Recheck delivery at 900 rpm checkpoint.
(15) Check governor cutoff at 950 rpm.
(16) Speed droop device test and adjustment.
(a) After normal pump test, check full-load
governor regulation by moving the throttle lever tow-
ard the closed position until the pump is on governor
at full-load speed. 1800 (60 Hz), 1500 (50 Hz), 2000
(400 Hz). This will be indicated by a difference in de-
livery sound and a slight reduction of fuel delivery
(1-2cc/1000 strokes) when a draw is taken into the
graduates. Hold the throttle in this position with the
standard vernier rack positioner supplied with most
test benches. Do not position throttle by means of
high- speed adjusting screw.
(b) Increase test stand speed. Record speed
where fuel delivery falls to 116-120 cubic millimeters
per stroke (1500 rpm or 50 Hz) or 114-118 cubic milli-
meters per stroke (1800 rpm or 60 Hz). This speed is
known as no-load speed and should not be higher than
the percentage or the high idle speed 1836 rpm (60 Hz),
1545 rpm (50 Hz). If, for example, the unit operates
at 1500 rpm full-load and 3 percent regulation is re-
quired, no-load speed will be:
1500 x 0.03=45
45 = 1545
At 1545 rpm, the pump should not deliver more than
116-120 cubic millimeters per stroke at 50 Hz;
114-118 cubic millimeters per stroke at 60 Hz.
(c) If high idle, no load speed, as described
above, is too low, adjust by means of the knurled
knob at the rear of the pump housing. This is the
The knob should be turned clock-
wise to raise the no-load speed 1836 rpm (60 Hz);
1545 rpm (50 Hz).