CROSS SECTION OF FUEL SYSTEM

FUEL SYSTEM

SYSTEMS OPERATION

(90N1-90N6120)

CROSS SECTION OF FUEL SYSTEM

11. Fuel transfer pump. 13. Camshaft. 14. Housing for fuel injection pumps. 15. Lever. 16. Governor housing. 17.

Load stop pin. 18. Cover. 19. Sleeve control shafts (two). 20. Inside fuel passage. 21. Drive gear for fuel transfer

pump. 22. Lever on governor shaft. 23. Governor springs (inner spring is for low idle: outer spring is for high idle). 24.

Spring seat. 25. Thrust collar. 26. Over fueling spring. 27. Load stop lever. 28. Carrier and governor weights. 29.

Sleeve levers.

From fuel transfer pump (11), fuel under

When starting the engine, the force of over

pressure, fills the housing for the fuel injection

fueling spring (26) is enough to push thrust collar

pumps (14). Pressure of the fuel in housing (14) is

(25) to the full fuel position. This lets the engine

controlled by bypass valve (12). Pressure of the

have the maximum amount of fuel for injection

fuel at FULL LOAD is 30 5 psi (2.1 0.4

when starting. At approximately 400 rpm, gover-

nor weights (28) make enough force to push spring

kg/cm2). If the pressure of fuel in housing (14)

(26) together. Thrust collar (25) and spring seat

gets too high, bypass valve (12) will move (open)

(24) come into contact. From this time on, the

to let some of the fuel return to the inlet of fuel

governor works to control the speed of the engine.

transfer pump (11).

When governor springs (23) are put in compres-

Lever (15) for the governor is connected by

sion, the spring seat at the front of the governor

linkage and governor springs (23) to the sleeve

springs will make contact with load stop lever (27).

control shafts (19). Any movement of lever (22)

Rotation of the load stop lever moves load stop pin

will cause a change in the position of sleeve control

(17) up until the load stop pin comes in contact

shafts (19).

with the stop bar or stop screw. This stops the

movement of thrust collar (25), the connecting

When lever (15) is moved to give more fuel to

levers, and sleeve control shafts (19). At this

the engine, lever (22) will put governor springs (23)

position, the maximum amount of fuel per stroke

in compression and move thrust collar (26) for-

is being injected by each injection pump.

ward. As thrust collar (25) moves forward, the

connecting linkage will cause sleeve control shafts

The carrier for governor weights (28) is held on

(19) to turn. With this movement of the sleeve

the rear of camshaft (13) by bolts. When engine

control shafts, levers (29) will lift sleeves (30) to

rpm goes up, injection pump camshaft (13) turns

make an increase in the amount of fuel sent to the

faster. Any change of camshaft rpm will change the

engine cylinders.