8.
9.
If fuel tank is disconnected, use
a
separate container
of
fuel
and connect a short hose line between the transfer pumpinlet
and the fuel container. The pump has enough suctlon
(1
5
to
18
inches
[381
to
399
mm]
of vacuum) to
pull
the fuel
out
of the
container.
Continue transfer pump operation while assistant
rotates flywheel slowly in clockwise direction.
TIMING BUTTON THICKNESS
Injection
pump
kits
a
pump
and
four
buttons
which will time 90 percent of the engines. The
standard thickness button and ring spring are no
longer assembled, but are loose
in
kit.
Stop flywheel rotation at exact point
fuel
stops
flowing from
No.
1
lineintocontainer(onedropin
2
to
5 seconds).
l-his
point
is
the
port
closing
time
of
the
injection
pump
plunger
regardless
of
flywheel position, Figure 34.
Pump timing is critical. The injection pump on each
engine must be timed
to
that particular engine by
using a timing button of specific thickness. Use the
method which applies best to determine the correct
new button thickness. Each new pump has its own
port closing dimension stamped on it.
FILL
PORT
(PC)
FIGURE
34.
PORT CLOSING
Timing is correct if port closing occurs when the PC mark on
the flywheel aligns with the timing pointer. If it doesn't match,
timing is either early
or
late and another timing button is
required, Figure
35.
FIGURE
35.
PORT CLOSING (PC) MEASUREMENT
Procedure
1.
Mark flywheel in 0.1-inch (2.54 mm) graduations
(about five marks each direction) from PC mark
for calculating required change
in
button
thickness.
2. Measure distance in tenths (or mm) from PC mark
on flywheel to point of actual port closing.
3. Multiply distance measured times .003 inch
(.076 mm) to determine the difference in
thickness required for new button.
One degree of crankshaft rotation equals the 0.1-inch gradua-
tion or .OO&inch button thickness for timing.
TIMING CALCULATION
0.3'
x
.003"
=
.009"
(7.6 x .076
=
.228
mm)
Example
A.
The port closing time
is
late
by 0.3-inch
(7.6 mm) measurement, Figure 36.
POINTER POINTER
EXAMP
LEA
'
FLYWHEEL
FIGURE 36. TIMING MARKS
Since .1 inch (2.54 mm) equals .003 inch (7.6 mm)
button thickness, the installed button is too thin by
.009 inch (0.229 mm). This means a button
.009
inch
(0.229 mm) thicker than the one installed is required
to time port closing
so
PC mark on flywheel aligns at
the timing pointer when fuel flow stops.
Example B.
If
PC
timing is
too
early by 0.4 inch
(10.2 mm), multiply 0.4
x
.003 = .012 inch (10.2 mm
x
'7.6 mm
=
0.305 mm).
In
this case, a thinner button
.012 inch (0.305 mm) less than the one installed is
required.
28
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