Fuel/Lubrication/Cooling SPECIAL TOOLS A number of special tools must be available to the technician when performing service procedures in this section. Description
p/n
Tachometer
0644-275
Oil Pressure Test Kit
0644-495 DE078B
NOTE: Special tools are available from the Arctic Cat Service Department.
Diesel Fuel Injection System The diesel engine in this Arctic Cat ATV is a “compression ignition” engine. Extremely high pressure in the combustion chamber raises air temperature high enough to cause ignition of the fuel upon injection into the combustion chamber. No spark is present or required for ignition. In this style of engine, diesel fuel is drawn from the fuel tank by a low pressure lift pump. From the lift pump, fuel is pumped through the fuel filter/fuel shut-off and delivered to the fuel rail. Low pressure fuel at 0.42-0.56 kgcm2 (6-8 psi) flows to the unit injectors (high pressure fuel pump/fuel injector) where the fuel pump, driven by a special lobe on the camshaft, increases the fuel pressure to 143-153 kg-cm2 (2030-2175 psi). At this point, the fuel is atomized by the fuel injector nozzle as it enters the combustion chamber. Fuel in excess of the amount required for any particular power setting is directed back into the fuel return side of the fuel rail and routed back to the fuel filter head where it either recirculates or is returned to the fuel tank via the fuel return hose.
DE309A
2. While holding pressure against the lift pump push rod, rotate the engine until the push rod is fully retracted. NOTE: If pressure is not applied to the push rod while rotating the engine, the push rod may become dislodged from the eccentric ring requiring valve cover removal to relocate.
INSTALLING 1. Using a new O-ring, place the fuel pump onto the cylinder head and secure with the existing hardware. Tighten the nuts alternately until the fuel pump is seated against the head; then tighten securely.
Fuel flow is shut off when the ignition switch is turned to the OFF position. A fuel solenoid valve is located on the fuel filter head and opens the valve whenever a 12 DC volt current is applied to the solenoid.
Lift Pump REMOVING 1. Remove the banjo-fitting bolts securing the fuel hoses to the lift pump; then remove the two nuts securing the lift pump to the cylinder head. Account for four crush washers, an O-ring, and two flat washers.
108
DE530
2. Connect the fuel inlet and lift pump outlet hoses to the fuel lift pump using new crush washers and secure with the banjo-fitting bolts. Tighten securely.
