TM 5-4320-218-15
the pump unit is shown in figures 6 and 7.
14. Operating Details
(1) Pump capacities are shown in gallons
a. Set the idling speed when the unit has
per minute. Pump discharge pressures
been operated long enough to become warm.
are shown `in pounds per square inch
Adjust the throttle until the minimum steady
and in feet of head of the liquid
idling speed is obtained. Screw the low-speed
pumped.
adjustment of the carburetor in or out until the
(2) These two sets of curves are for fuels
engine runs steady and as fast as the throttle
of different specific gravities.
position will permit in accordance with para-
(3) Lines of constant brake horsepower
graph 58b.
represent the loading of the engine for
b. The horsepower required to drive the
pump varies with the weight of the liquid being
various pumping conditions. They are
characteristic of the Wisconsin MVG4
pumped and the capacity or rate of pumping. To
D engine and apply to both curves.
prevent overloading, the engine throttle should
This engine will give satisfactory serv-
be adjusted so as to have at least 5 inches vacu-
ice as long as the brake horsepower
um on the engine vacuum gage regardless of
does not continuously exceed the
liquid being pumped or the rate of pumping
maximum continuous performance
and regardless of speed of the engine.
shown on the curves.
C. A composite pump performance curve for
Figure 6. Performance of pump unit pumping gasoline @ 0.70 specific gravity.