Testing Pump; Testing Check Valves - Arctic Cat Sno Pro 120 Service Manual

800 cc
1. On the 500/570 cc models with the engine off, discon-
nect the throttle cable from the throttle lever. Pull the
throttle cable to the Full-Open position; then using a suit-
able clamping device, secure the cable in this position.
CAUTION
Care must be taken when securing the cable not to
kink or damage the cable.
2. On the 500/570 cc models, if the marks are not
aligned, adjust synchronization by loosening the jam
nut(s) on the adjuster. Rotate the jam nuts/adjuster
nut until proper alignment is attained. Tighten jam
nut(s).
3. On the 500/570 cc models, connect the throttle cable to
the throttle lever; then adjust the cable/linkage adjust-
ing nut so the throttle lever moves approximately 1/8
in. before the oil-injection pump control arm begins to
move. This ensures the throttle/ignition monitor switch
will function properly and prevents ignition "cut-out"
and spark plug fouling at low RPM operation
4. On the 800 cc models, rotate the control rod until the set-
ting for oil pump at wide open throttle is 1 to 1.5 lines
lean. Return the control rod/throttle cable to the Idle
position.
CAUTION
Assure the throttle cable/linkage has returned to the
fully closed (idle) position and has not remained par-
tially open and moves freely from the open position to
the closed position.

TESTING PUMP

 NOTE: These tests must be made with the snowmobile
and oil at a "room" temperature of 20°-30° C (68°-86° F).
! WARNING
Always wear safety glasses when performing this test.
1. Disconnect the oil pump cable/control rod from the
control rod on the pump.
2. Clamp off the oil-supply hose between the oil reser-
voir and oil pump; then remove the supply hose from
the pump.
3. Attach a suitable length of clear oil-supply hose to the
oil pump; then using Oil Injection Usage Tool, fill the
hose with Arctic Cat Synthetic APV 2-Cycle Oil.
4-28
 NOTE: Do not fully insert the usage tool into hose.
There must be enough room around the tip of the tool
and the hose to allow air in the hose to escape.
4. Fill the tool to the 0 line.
5. Wipe the tip of the tool to remove excess oil; then attach
the tool to the oil-supply hose and remove the bulb.
6. Secure the tool to the oil reservoir by twisting the
rubber strap one half turn and placing the rubber
strap around the tool and the oil reservoir filler neck.
 NOTE: On the F570, the tool can be secured to the
air silencer.
0746-376
 NOTE: On the F/M/XF to access the oil pump, the air
intake boot must be removed.
 NOTE: On the 800 cc, the control rod must be
secured in the Idle position. Secure the rod away
from any moving parts to prevent misalignment of the
control rod due to engine/chassis movement.
Keep hands and clothing away from all moving or
rotating parts.
7. With the control rod secured in the Idle position, start
the engine and run the engine at recommended RPM
for 3 minutes. Compare the amount of oil used
against the specifications listed.
ENGINE
500 cc 1833
570 cc 2000
800 cc 1833
 NOTE: Before starting the engine, make sure that
no air is present in the testing equipment.
8. With the control rod secured in the Full-Open position
(line-to-line), run the engine at recommended RPM for
2 minutes. Compare the amount of oil used against the
specifactions listed.
ENGINE
500 cc 1833
570 cc 2000
800 cc 1833
9. If the oil-injection pump output does not meet the
specifications, see TESTING CHECK VALVES in
this sub-section.
10. Disconnect the oil usage tool, remove the plug from
the reservoir, and attach the oil-supply hose to the oil
reservoir.
 NOTE: After testing the oil pump, the oil pump must
be correctly synchronized with the carburetors/throt-
tle bodies (see SYNCHRONIZING in this sub-section).

TESTING CHECK VALVES

If an engine problem occurs due to lack of lubrication,
the check valves should be tested using a vacuum pump
to make sure they are operating properly.
! WARNING
RPM Full-Closed (Idle) 3 Minutes
1.0-2.5 cc
1.4-2.2 cc
1.32-3.48 cc
RPM Full-Open 2 Minutes
7.4-10.3 cc
6.9-9.4 cc
8.74-10.8 cc