17626-Z07-R30 Honda VALVE, BREATHER

Engine Design
Bore ... 4.75 in.(120.65 mm)Stroke ... 6.0 in.(152.40 mm)Number of Cylinders ... 4Cylinder Arrangement ... *in-lineFiring Order (Injection Sequence) ... 1, 3, 4, 2Direction of Rotation (when seen from flywheel end) ... Counterclockwise*No. 1 Cylinder is Opposite Flywheel End.Fuel System
SCHEMATIC OF FUEL SYSTEM
1. Constant bleed valve. 2. Disc. 3. Siphon break orifice. 4. Priming pump. 5. Fuel injection pump. 6. Fuel injection valve. 7. Bleed valve. 8. Fuel return line. 9. Fuel supply line [water separator (W.S.) installation is shown by dash lines]. 10. Fuel tank. 11. Fuel filter. 12. Channel. 13. Check valve. 14. Check valve. 15. Housing for the fuel injection pumps. 16. Passage. 17. Check valve. 18. Bypass valve. 19. Passage. 20. Transfer pump.Introduction
The Sleeve Metering Fuel System is a pressure type fuel system. The name for the system is from the method used to control the amount of fuel in the fuel injection charge. This system has an injection pump and an injection valve for each cylinder. The injection pumps are in the fuel injection pump housing on the right side of the engine. The injection valves are in the precombustion chambers in the cylinder head.Fuel Flow With Engine Running
When the engine is running, transfer pump (20) pulls fuel from fuel tank (10), through fuel filter (11), and into channel (12). Channel (12) is behind the cover on the side of housing (15) for the fuel injection pumps. From the channel, the fuel goes through check valve (13) into the bottom of priming pump (4). Through priming pump (4), out check valve (14) and into passage (19) to transfer pump (20). The output of the transfer pump goes into housing (15).The fuel in the housing is the supply for the injection pumps and the lubricant for all the moving parts in the housing. Fuel can go from the housing in three ways.1. Fuel injection pumps (5) send some fuel to the cylinders during injection. 2. Constant bleed valve (1) lets approximately 9 gal./hr. of fuel go back to the fuel tank, through return line (8) when the pressure in the housing is 25 to 32 psi (170 to 220 kPa). This flow takes air and heat away from the housing.
CONSTANT BLEED VALVE
1. Constant bleed valve (in fitting).3. Bypass valve (18) keeps the pressure of the fuel in the housing at a maximum of 25 to 32 psi (170 to 220 kPa) at 2200 rpm. Fuel which goes through the bypass valve mixes with the fuel flow from the tank in passage (19). From here the mixture of fuel goes through the transfer pump and back into the housing.Fuel Flow Using The Priming Pump And Bleed Valve
When the priming pump handle is pulled out, negative air pressure in the pump makes check valve (13) open and pulls fuel from the tank. Pushing the handle in closes check valve (13) and opens check valve (14). This pushes air and/or fuel into the housing through passage (16) and check valve (17). More operation of the priming pump will pull fuel from the tank until fuel supply line (9), fuel filter (11) and housing (15) are full of fuel. At this time the fuel flow from the bleed valve (7) will have no air bubbles.Fuel Flow After Engine Stops Running
When the engine is running, the pressure in the housing holds some air in the fuel in a mixture. When the engine stops, the air comes out of the fuel and goes to the top of the housing. The air goes out of the housing through hole (21) in the cover and into passages (22) and (25) in the filter base. The air goes under disc (2), through scratch (26) and down through passages (27), (23), and (24). Then the air goes through the top of the filter housing and the remainder of the fuel stays in the housing and filter.
SIPHON BREAK HOUSING
21. Hole. 22. Passage. 23. Passage. 24. Passage.
SIPHON BREAK FUEL FILTER BASE
2. Disc. 25. Passage. 26. Scratch. 27. Passage.When the engine starts the next time, the fuel in the housing and in the filter will be the supply for the engine until the transfer pump pulls the fuel from the tank.Fuel Transfer Pump
The fuel transfer pump is on the front end of housing for the fuel injection pumps. The output of the pump is more than the engine needs for combustion. Camshaft (4) for the fuel injection pump turns drive gear (3) in the transfer pump. Two lip-type seals (6) on the camshaft keep the fuel in the transfer pump apart from the engine oil in the compartment for the timing gears. The area between the two seals is connected to transfer pump drain (8). The drain has two functions. One function is to be an outlet for fuel or lubrication oil leakage. The other function is to give a visual indication of seal or bearing failure before the failure can be a cause for any other failures.
FUEL TRANSFER PUMP
1. Seal. 2. Driven gear. 3. Drive gear. 4. Camshaft for the fuel injection pump. 5. Drive sleeve. 6. Lip-type seals.
FUEL TRANSFER PUMP BODY
7. Outlet for lubrication oil to automatic timing advance unit. 8. Transfer pump drain. 9. Inlet for lubrication oil for automatic timing advance unit.Water Separator
The water separator is installed between the fuel tank and the rest of the fuel system. For efficiency in the action of the water separator the fuel flow must come directly from the fuel tank and through the water separator. This is because the action of going through a pump or valves before the water separator lowers the efficiency of the water separator.The water separator can remove 95% of the water in a fuel flow of up to 33 gph (125 litre/hr) if the concentration of the water in the fuel is 10% or less. It is important to check the water level in the water separator frequently. The maximum amount of water which the water separator can hold is 0.8 pt. (0.4 litre). At this point the