Main Wiring And Safety Switches; Carburetor Safety Switches (570 Cc); Synchronizing Carburetor Safety Switches (570 Cc) - Arctic Cat Sno Pro 120 Service Manual

3. Move the throttle lever to the wide open position. The
meter must read OL (infinite resistance). If the meter
reads less than 1000 ohms, replace the control assem-
bly.
4. Connect one ohmmeter lead to the red/green wire
and the other lead to the red/violet wire. With the
emergency stop switch in the off position, the meter
must read OL (infinite resistance). If the meter reads
less than 1000 ohms, replace the control assembly.
With the emergency stop switch in the (RUN) posi-
tion, the meter must read less than 1 ohms. If the
meter reads OL (infinite resistance), replace the con-
trol assembly.

Main Wiring and Safety Switches

(570 cc)
1. Check the wire connections at the ignition key
switch and at the emergency stop switch. If any of
the connections appear dirty or corroded, clean with
contact cleaner and compressed air; then apply
Dielectric grease to all non-pin connectors and con-
nect all wires and squeeze connections until they are
securely locked.
 NOTE: To access the electrical connectors, the con-
sole must be removed.
2. Disconnect the main wiring harness connector coming
from the engine. Using an ohmmeter, connect one
lead to the black wire in the connector of the main
harness. Connect the remaining ohmmeter lead to the
violet/red wire in the connector of the main harness.
3. With all switches in the RUN position, the meter
must read infinite resistance (OL). If the meter reads
less than 1 ohm resistance, proceed to Emergency
Stop Switch and Ignition Switch sub-sections in this
section and the following Carburetor Safety
Switches.

Carburetor Safety Switches (570 cc)

1. If the meter read infinite resistance (OL) in the previ-
ous test, disconnect the carburetor safety switches
one at time and test for a closed circuit.
2. Attach the two ohmmeter leads to the two leads com-
ing from each carburetor switch. The meter must
read less than 1 ohm resistance.
3. If the meter reads infinite resistance (OL), the switch
must either be adjusted or replaced (proceed to the
following Synchronizing
Switches). If the meter reads less than 1 ohm resis-
tance, see Ignition Switch sub-section in this section.
Synchronizing Carburetor Safety
Switches (570 cc)
Before synchronizing the carburetor safety switches, ver-
ify the idle speed screws are adjusted equally and the pis-
ton valves are synchronized. The carburetor safety
switches affect ignition spark at idle only. If ignition
spark problems are observed at partial or full-throttle
positions, the problem is not with the carburetor safety
switches.
 NOTE: The correct throttle lever/control housing
gap is a range of 0.375-0.500 in. the moment the
meter reading changes from open to closed. A switch
that changes from open to closed before the other
one is the switch that must be raised to attain safety
switch synchronization.
 NOTE: After completion of any adjustments, throttle
Carburetor Safety
lever "side pressure" should not cause an ignition
miss at idle. Carburetor switches set too low or an
excessively tight throttle cable makes the shutdown
system very sensitive to throttle lever "side pres-
sure" near idle. To test carburetor safety switch syn-
chronization, follow steps 5-9.
1. Inspect the cable free-play gap between the throttle
lever and the control housing at idle. Adjust the
throttle cable swivel adapter at the top of each carbu-
retor for 0.030-0.060 in. cable free-play gap between
the throttle lever "nibs" and the control housing.
While observing if there is any cable free-play gap,
apply slight pressure to the throttle lever to take up
any cable slack that may be present. However, do not
apply enough pressure to actually raise the carbure-
tor slides during this adjustment. After cable free-
play is properly adjusted, tighten the jam nut on each
carburetor securely.
2. To determine which switch needs adjusting, discon-
nect both carburetor safety switches from the main
wiring harness connector.
3. Connect a digital ohmmeter to one carburetor safety
switch connector; then compress the throttle lever
while observing the meter reading and measure the
gap between the throttle lever and control housing at
the moment the meter reading changes from open to
closed. Repeat this step for the other carburetor
safety switch.
4. If an adjustment is necessary, loosen the switch
bracket screws, move the switch up, tighten the
screws, and then reset using step 3.
5. Reconnect the carburetor safety switch connectors.
Place the rear of the snowmobile on a shielded safety
stand; then start the engine and allow it to warm up
for 3-4 minutes.
6. Hold both the top and bottom of the throttle lever pin
so that depression of the throttle lever does not move
the lever pin in its control slot.
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