106
Fuel/Lubrication/Cooling
SPECIAL TOOLS
A number of special tools must be available to the techni-
cian when performing service procedures in this section.
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 “compres-
sion ignition” engine. Extremely high pressure in the
combustion chamber raises air temperature high enough
to cause ignition of the fuel upon injection into the com-
bustion chamber. No spark is present or required for igni-
tion.
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 deliv-
ered to the fuel rail. Low pressure fuel at 0.42-0.56 kg-
cm
2
(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-cm
2
(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.
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 wash-
ers.
DE078B
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.
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.
Description
p/n
Tachometer
0644-275
Oil Pressure Test Kit
0644-495
