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 CAUTION
NOTE
Do not use undue force in screwing
The cleaning of spray orifices is a
down the housing (9) or retainer (11),
delicate operation requiring good
or the parts may be distorted and
light and a magnifying glass. The
cause needle to bind in sleeve.
cleaning tool must be inserted into
(6) Screw housing (9) firmly into body (12).
the orifices gently with a rotating
(7) Install ball (3) and tighten plug (2). Install
motion. No attempt should be made
a new gasket (8) before installing the filter (6). Place
to push tool into orifices if they are
filter (6) into body (4), then screw body (4) into body
filled with hard carbon or other dirt.
(12).
Discard tip, and needle, when either
f. Testing.
show signs of discoloration at tip.
(1) Place fuel injector in tester. Prime the
(2) Using a magnifying glass, examine the
tester by using very quick strokes until some fuel is
spray orifices in the tip. Compare them with those in a
ejected from injector in a fine spray. Then pump with
new tip. If the edges appear ragged or distorted, discard
slow even strokes.
When the injector is working
the tip.
properly, a continuous uniform "popping" will occur.
(3) Clean the tip thoroughly. If the tip cannot
(2) When opening pressure has been
be properly cleaned, discard it and replace it with a new
reached, the needle will lift from its seat and quick
tip.
pressure drop will be indicated on gage. The highest
(4) Clean the tip seat in body. Dip the needle
pressure reached before this drop, as indicated on the
(13) in clean fuel oil and place it in the sleeve (14).
gage, will be the opening pressure.
Remove needle from sleeve. Wipe needle clean with a
(3) Check the spray pattern of the injector.
lint free cloth. Inspect needle seat, if scratched or
All fuel injector sprays in the engine should be of the
pitted, replace the needle and sleeve.
same density and provide an even spray in all
NOTE
directions. The needle should return to its seat sharply
Needle and sleeve are lapped
when pumping ceases.
together when new, and must be
(4) Check the fuel injector opening pressure
replaced together at the same time.
((2) above). The fuel injector should open at 2,500 psi.
(5) When the needle seat has been
If the injector opens before 2,500 psi, remove shims
inspected, and found in good condition, wipe needle dry.
(22) from under the retainer (1). If injector opens after
Place it in the sleeve. If it will fall into place by its own
2,500 psi, add shims under retainer (1).
weight, it is considered to be free and will not bind in the
NOTE
sleeve.
Shims (22) are available in 0.004 in.,
(6) Inspect ball (3). If out of round, replace.
0.0149 in., and 0.0299 in. sizes.
(7) Inspect filter (6). If broken or damaged,
These shims will change pressure by
replace it.
approximately 100 psi, 400 psi, and
(8) Prior to reassembly, clean all parts again
1,000 psi respectively.
in clean fuel oil. Assure that threaded items, and all
NOTE
parts are carbon free. Wash again in clean fuel oil and
Prior to installing fuel injectors in the
blow dry with compressed air.
cylinder head, install a new gasket
NOTE
(17) in the cylinder head fuel injector
The spring push rod (19) causes very
port.
little injector trouble and should not
g. Installation. Install in reverse order of the
have to be replaced.
If for any
removal (fig. 3-14). Turn on fuel to engine (34, table 2-
reason the push rod must be
replaced, it and the stop (11) must be
lightly lapped in place.
3-13. Governor (Mechanical)
e. Reassembly.
a. General. The governor is a flyball (weighted)
(1) Place a new gasket (15) on tip (16) and
type, having a vertical spindle driven from the camshaft
insert tip and gasket in body (12).
by a flexible driver gear. As the engine speed increases
(2) Use a square end soft metal rod to tap the
or decreases, because of load variations, the weights
tip into its seat in the body.
swing in and out and force the governor yoke up, or
(3) Place the needle (13) and stop (11) in
down. The governor yoke is connected through linkage
sleeve (14). Insert this subassembly into body (12) on
to the fuel control shaft, which turns slightly on its axis
top of tip (16).
as the yoke moves. The governor spring is designed to
(4) Install retainer (18) with tapered end up.
give a specific resistance to the centrifugal force on the
Install a new gasket (10).
weights, and it allows the yoke to move the desired
(5) To assemble the housing (9), first insert
amount for certain speed changes. The governor is
the push rod (19) in housing with the large rounded end
lubricated by the engine lubrication system.
at the top, then install seat (20), spring (21), shim (22),
b. Removal and Disassembly.
and retainer (1).
(1) Disconnect the oil line from spray tip (3,
3-42
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