Arctic Cat Sno Pro 120 2011, Service Manual

Page: 265 / 535

5-4
2. Crank the engine over and check for spark. If no
spark is present, check to make sure the throttle cable
is properly tensioned. Compress the throttle control
and while holding the throttle control in this position,
crank the engine over and check for spark. If spark is
now present, adjust the throttle cable tension.
3. If no spark is present, disconnect the main wiring
harness from the engine. Crank the engine over. If
spark is present, the problem is either one or more of
the following.
A. Defective emergency stop switch
B. Defective safety switch in throttle-control hous-
ing
C. Grounded or shorted wire connection at the throt-
tle-control housing or main wiring harness
D. Defective ignition switch

NOTE: To check these possible causes, proceed to
the following TESTING sub-section.
TESTING
Main Wiring and Safety Switches
1. Check the wire connections at the ignition key
switch and at the emergency stop switch. This con-
nector is located on the front side of the steering
post. If any of the connections appear dirty or cor-
roded, clean with contact cleaner and compressed
air; then apply Dielectric grease to all non-pin con-
nectors and connect all wires and squeeze connec-
tions until they are securely locked.

NOTE: On the F570 to gain access to the electrical
connectors, the console 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
brown wire in the connector of the main harness.
3. With all switches in the RUN position, the meter
must read resistance (closed). If the meter reads no
resistance (open), proceed to testing Emergency
Stop/Throttle Switch, Ignition Key Switch, and Car-
buretor Safety Switches.
Emergency Stop/Throttle Switch
1. If the meter read no resistance (open) in the previous
test, locate the wiring harness coming from the emer-
gency stop/throttle switch assembly.
2. Disconnect the three-wire connector. Using an ohmme-
ter, connect one meter lead to the black wire and the
other meter lead to the black/red wire in the connector.
3. With the emergency stop knob, located on top of the
throttle control, in the ON (pulled up) position and
the throttle lever compressed, the meter must read
resistance (closed).
4. If the meter reads no resistance (open) and the lever/
control housing free-play is correct, replace the
throttle switch.
5. If the meter reads resistance (closed) but the engine
will not start, with the ohmmeter leads still connected,
alternately release and compress the throttle lever;
then move the emergency stop knob down and up.
6. The meter must read no resistance (open) when the
throttle lever is released and the emergency stop
knob is in either the UP or the DOWN position.
7. If the meter reads resistance (closed), replace the
throttle switch.
8. Connect one meter lead to the black/red wire and the
other meter lead to the black/white wire.
9. With the throttle lever released (idle position) and
the emergency stop knob in the DOWN position, the
meter must read no resistance (open).
10. If above tests were good, proceed to testing Ignition
Key Switch and Carburetor Safety Switches.
Ignition Key Switch
1. If the meter read resistance (closed) in the previous
test, disconnect the ignition key switch connectors
and connect the ohmmeter leads to each of the leads
from the switch.
2. With the key switch in the OFF position, the meter
must read resistance (closed). If the meter reads no
resistance (open), replace the switch.
Carburetor Safety Switches
1. If the meter read no resistance (open) in the previous
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 resistance (closed).
3. If the meter reads no resistance (open), the switch
must either be adjusted or replaced (proceed to Syn-
chronizing Carburetor Safety Switches in this sub-
section). If the meter reads resistance (closed), see
testing Ignition Key Switch.
Synchronizing Carburetor Safety
Switches
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.
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.
Manual
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