5030968 JOHNSON PISTON ASSY., 0.50mm O.S.

Table 1
Required Tools
Tool Part Number Part Description Qty
A 268-1968 Pry Bar 1 Start By:
Remove the valve mechanism cover.
Remove the fuel line.
Illustration 1 g01264292
Illustration 2 g01264293Note: To reduce the risk of contamination to the system, do not remove the quill tube.
Fully loosen quill tube nut (1). Pull quill tube (1) out of the bore until you see O-ring seal (2). Ensure that the injector does not contact the quill tube during removal. At this time, inspect O-ring seal (2) for wear or for damage. Replace the O-ring seal if necessary.
Illustration 3 g01356104
Disconnect harness assembly (3) from unit injector (4).
Remove nuts (6) and position harness assembly (5) out of the way.
Illustration 4 g01356114
Remove bolt (7) from clamp (8). Note: When possible, remove the unit injector by hand by twisting the unit injector and pulling upward. Be sure not to strike the unit injector during the removal procedure.
If unit injector (4) cannot be removed by hand, go to Step 6.
Illustration 5 g01356125Note: Do not damage the unit injector during removal. Side loading may damage the unit injector.
Position Tooling (A) under unit injector clamp (8). Carefully remove unit injector (4) from the cylinder head. Installation Procedure
Table 2
Required Tools
Tool Part Number Part Description Qty
B - Scotch Brite 1
C 1U-5718 Vacuum Pump 1
169-7372 Bottle Assembly 1
4C-4057 Clear Plastic Tubing
7.92 mm (0.312 inch) OD 1
4C-4055 Clear Plastic Tubing
6.35 mm (0.250 inch) OD
D 9U-5470 Reamer 1
E 4C-6161 Tube Brush 1
F 9U-6862 Tapered Brush 1
G 4C-6774 Vacuum Gun Kit 1
H 4C-5027 Tap Wrench 1
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Evacuate as much fuel and oil as possible from the cylinder head before installing the unit injector. Several evacuations may be necessary. Use Tooling (C) to remove the fuel and oil from the cylinder. Note: Tooling (F) is available to clean loose material from the sleeve bore and the cylinder.
Clean the carbon from the sleeve, the sleeve bore, and the end of the unit injector. Clean the carbon from the seat area that is inside of the cylinder head. A fine grade of Tooling (B) is preferred. Clean the carbon from the cylinder head. If the sleeve has been removed from the engine, use Tooling (D) to remove only carbon from the surface of the sleeve. If the sleeve is installed in the engine, use Tooling (E) to clean the carbon deposit from the inside of the sleeve. The following procedure is the preferred method of cleaning the sleeve bore.Place a 38 mm (1.5 inch) square piece of Scotch Brite material on the end of Tooling (F). Twist Tooling (F) with Tooling (H) against the lower surface of the sleeve bore.The surface should be cleaned until the surface is smooth and shiny. The entire sleeve bore should be cleaned in order to remove any loose carbon particles.Note: Tooling (G) is available to clean loose material from the sleeve bore and the cylinder.
The correct procedures and tooling specifications must always be used. Failure to follow any of the procedures may result in damage, malfunction, or possible engine failure.