1. Rocker injector arm. 4. Fuel injector.
2. Push rod.
5. Injector follower.
3. Lock nut.
6. Injector timing
Figure 5-27.Timing gauge.
1. The governor speed control lever should be in
the IDLE position. If a stop lever is provided,
secure it in the STOP position.
2. Rotate the engine crankshaft, using an engine
barring tool, until the exhaust valves are fully
depressed on the cylinder that you wish to set the
injector. If a barring tool is not available, a 3/4-
inch-square drive socket set with a suitable
socket to fit over the crankshaft pulley will also
3. Insert the small end of the timing pin (gauge)
into the hole provided in the top on the injector
body, with the flat portion of the gauge facing
the injector follower.
4. Gently push the gauge by holding the knurled
stem with the thumb and forefinger towards the
follower. There should be a slight drag between
the gauge and the follower.
5. If this cannot be done, loosen the injector
pushrod locknut and adjust it until the drag of
the gauge (slight feel) has been determined.
Hold the pushrod and tighten the locknut.
Recheck the feel, and, if needed, readjust.
When hot setting this adjustment, wipe off the
top of the injector follower and place a clean
drop of oil on it. When properly adjusted, the
gauge should just wipe off the oil film from the
follower when the slight drag is felt.
Time remaining injectors in the same manner.
Since all the injector racks are connected to the fuel
control tube and then to the governor by the fuel rod or
rods, they must be set correctly. This ensures that they
are equally related to the governor. Their positions
determine the amount of fuel that will be injected into
the individual cylinders, ensuring equal distribution of
the load. Failure to set the racks properly will result in
poor performance and a lack-of-power complaint.
Adjusting the inner and outer adjusting screws on
the rack control lever (fig. 5-27) equalizes the injectors.
This is a rather delicate adjustment. and it may be
necessary to make these adjustments several times
before the engine operates just right.
To increase the amount of fuel injected, loosen the
outer adjusting screw and tighten the inner adjusting
screw, thereby moving the control rack inward. To
decrease fuel injection, loosen the inner adjusting screw
slightly and tighten the outer adjusting screw which
moves the control rack outward. In making the
operating adjustments, never turn the adjusting screws
more than one-fourth turn at a time; for if one injector is
adjusted too far out of line with the others, it will prevent
the full travel of the racks and reduce the maximum
power to the engine.
For exact procedures for adjusting the
injector rack control levers, refer to the
manufacturers service manual.
Sometimes smoother engine operation can be
obtained by making slight changes to the adjustments
after the engine is warmed to operating temperature
(above 140°F). For example, one cylinder may not be
carrying its share of the load as indicated by a
comparatively cooler cylinder. Therefore, the control
rack should be adjusted for more fuel. A slight
knocking noise from another cylinder would indicate an
adjustment for slightly less fuel.