12251-ZY3-A01 Honda GASKET, CYLINDER HEAD (NIPPON LEAKLESS)

1. Disconnect the wires (not shown) from the starter. Fasten a hoist to the starter. Remove three bolts (1) and remove starter (2). Remove the gasket. The weight of the starter is 29 kg (64 lb).2. Remove plug (3) from the flywheel housing. 3. Install tooling (A) in the flywheel housing. No. 1 piston at top center (TC) on the compression stroke is the starting point for all timing procedures. The engine is seen from the flywheel end when direction of crankshaft rotation is given.4. To find top center compression stroke for No. 1 piston, first turn the flywheel clockwise (opposite the direction of engine rotation) approximately 30 degrees. This procedure is to remove all play from the timing gears. Turn the flywheel counterclockwise until a 3/8"-16 NC bolt (4) can be installed in the flywheel through the hole in the flywheel housing. The No. 1 and No. 6 pistons are now at top center position.
If you go past the bolt hole you must start over with Step 2.
5. Remove breather (5) from the valve cover. 6. To see if the No. 1 piston is on the compression stroke, look at the valves of the No. 1 cylinder. The valves will be closed if No. 1 cylinder is on the compression stroke. You must be able to move both rocker arms (6) up and down with your hand.7. If No. 1 piston is not on the compression stroke, remove the 3/8"-16 NC bolt (4) and turn the flywheel 360° counterclockwise. Install the 3/8" bolt as before. The No. 1 piston is now at top center (TC) on the compression stroke. 8. Remove cover (7) from the front of the timing gear cover. 9. Install timing pin (8) [tool (C)] through the left top hole (as seen from the front of the engine) in the fuel injection pump gear and through the groove (slot) in the sleeve and into the hole in the adapter of the fuel injection pump. If the timing pin can not be installed at this time, install the timing pin after the fuel injection pump is removed.10. Loosen bolt (9) that holds the fuel injection pump gear to the sleeve approximately 3.2 mm (.125 in).11. Install tooling (B) and loosen fuel injection pump gear (11) from the sleeve. Remove tooling (B). Remove bolt (9) and washer (10).12. Disconnect the fuel return line from bypass valve. 13. Remove fuel injection lines (12) from the engine. Put plugs or caps on all the openings. 14. Remove oil supply line (13).15. Remove fuel supply lines (14) and (15).16. Put plugs or caps in the openings. 17. Remove bolts (16) that hold the fuel injection pump spacer to bracket (17).18. Remove three nuts (19) and remove fuel injection pump and governor (20). Remove the O-ring seal from the face of the fuel injection pump housing.19. If the timing pin was not installed in Step 9, turn the pump as needed to make an alignment of the groove (slot) in the sleeve with the hole in the adapter and install the timing pin (8) [tool (C)].20. Remove spacer (21). The following steps are for the installation of the fuel injection pump and governor.
Make sure the timing pin [tool (C)] is installed through the groove (slot) in the sleeve and into the hole in the adapter so the fuel injection pump timing is correct.
21. Make sure that the centerline of one of the holes in fuel injection pump gear (11) is 30° to the left of the vertical centerline of the fuel injection pump gear. This will permit the timing pin [tool (C)]to go through the hole in the fuel injection pump gear when the fuel injection pump and governor is installed. 22. Install the O-ring seal on the face of the fuel injection pump housing. Put fuel injection pump housing and governor (20) in position on the engine and against the timing gear plate. Make sure timing pin (8) [tool (C)] goes through the hole in the fuel injection pump gear as shown. 23. Install spacer (21) on the fuel injection pump housing (20).24. Install the three nuts (19) that hold the fuel injection pump housing and governor to the timing plate. Install bolts (16) that hold the fuel injection pump spacer (2) to bracket (17). 25. Install washer (10) and bolt (9) finger tight. 26. Install tooling (D) on the fuel injection pump gear as shown. 27. Put a torque wrench in tooling (D) with the wrench in line with the center of the fuel injection pump gear, and put a torque of 60 to 70 N m (45 to 50 lb ft) on the fuel injection pump gear to remove the gear clearance (backlash). While this torque is held, tighten bolt (8) to a torque of 149 7 N m (110 5 lb ft).28. Remove timing pin (8) [tool (C)].29. Put the gasket in place and install cover (7) on the front of the timing gear cover. 30. Install fuel supply lines (14) and (15).31. Install oil supply line (13).32. Install fuel injection lines (12) on the engine. Tighten the fuel line nuts to a torque of 40.7 6.8 N m (30 5 lb ft).33. Connect fuel return line to bypass valve.34. Install breather (5) on the valve cover.35. Remove tooling (A) from the flywheel housing.36. Remove bolt (4) from the flywheel.37. Install plug (3) in the flywheel housing.38. Fasten a hoist to the starter. Put the gasket in place and install starter (2) and bolts (1). Connect the wires (not shown) to the starter.