The most accurate method of injection pump timing
is
with
a
depth micrometer
(Method
7).
However, if a
depth micrometer is not available, time
it
by
Flowing
the
Pump
(Method
2).
the exhaust stroke.
Method
2.
Flowing
fhe
Pump:
1.
Install pump with 0.006-inch (0.15 rnm) shims
between pump and pad.
2.
Loosen the delivery valve holder to relieve
pressure on spring. See Figure
40.
3.
Rotate the flywheel
to
about
15
degrees before
the port closing (PC) point. Blow in the pump
inlet
and rotate the flywheel slowly clockwise
until airstopscoming outofthe pumpout1et.Thi.s
is
the
port closing point.
4.
Measure the distance from the point where port
closing occurs to the
PC
mark on the flywheel.
Find the thickness of shims to be added from the
table that follows.
..ââ
Injection pump must be timed on the compression stroke, not on
5.
Install the pump.
Method
7.
Depth Micrometer:
1.
Install pump tappet in its recess and position fly-
wheel on the port closing mark
(PC) of the com-
pression stroke.
2.
Using a depth micrometer, measure the distance
from the pump mounting pad on the crankcaseto
the tappet center. See Figure
39.
3.
Subtract from the port closing dimension of the
pump 1.670-inch
(42.42
mm) the depth obtained
in
step
2.
The result is the thickness
of
shims
necessary to time the pump correctly.
Thicknessof shims mayvaryfrom0.006 to0.052-inch (0.15 to
1.82mm).If itdoesnotfaliwithin
theselimits,checkcamshatt
and tappet for excess wear or improper assembly.
4.
Select the correct shims for the required thick-
5.
Install the pump.
ness.
FIGURE
39.
DEPTH
MICROMETER
FIGURE
40.
LOOSENING DELIVERY VALVE HOLDER
Installation
Prior to mounting the injection pump to the cylinder
block, follow steps
1
through
3.
1. Slide the shim or shims (using proper thickness
of shims for correct timing) over the pilot until
they are flat
on
the pump flange. See Figure 41.
2.
Dip the seal (O-ring)
in
engine lubricating
oil.
3.
Slide the seal over the pilot until tight against the
shim or shims.
43
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