Fuel Injector; Exhaust Temperature Sensor; Magneto Coil - Arctic Cat Sno Pro 120 Service Manual

1. Test between the two orange wires in the four-prong
connector from the magneto.
2. Resistance must be 1.52-2.28 ohms.
Injection Coil
1. Test between the two blue/white leads in the four-
prong connector harness from the magneto.
2. Resistance must be 15.2-22.8 ohms.
Lighting Coil
1. Disconnect the main harness from the magneto.
2. Connect the two meter leads to each of the yellow
leads in the connector from the engine.
3. Resistance must be 0.08-0.12 ohm.
Ignition Timing Sensor
1. Disconnect timing sensors 1 and 2 (green/white and
brown/green) from the main harness.
2. Connect the meter leads to the sensor leads.
3. Resistance must be 148-222 ohms.
Ignition Coil (Primary)
1. Disconnect the double wire plug from the main har-
ness to the ignition coil.
2. Connect the red meter lead to the black/white lead; then
connect the black meter lead to the white/blue lead.
3. Ignition coil primary resistance must be between
0.24-0.36 ohm.
Ignition Coil (Secondary)
1. Remove the spark-plug caps from the high tension
wires.
2. Connect the red meter lead to one high tension wire;
then connect the black meter lead to ground.
3. Resistance must be 5040-7560 ohms.
Spark-Plug Cap
1. Remove the spark-plug caps from the high tension
wires.
2. In turn on each cap, touch a tester lead to each end of
the spark-plug cap.
3. Resistance must be 4000-6000 ohms.
Ignition Switch
 NOTE: The console must be removed to access the
ignition switch.
1. Remove the main wiring harness connectors from
the ignition switch.
2. Rotate the key to the OFF position.
3. Resistance must read less than 1 ohm between the
ignition switch terminals.
4. Rotate the key to the RUN position. The meter must
read OL (infinite resistance).

Fuel Injector

1. Disconnect the fuel injector wiring harness; then set
the meter to the OHMS position.
2. Test between the two injector terminals. Resistance
must be 10-14 ohms.
3. If not within specifications, replace the injector.

Exhaust Temperature Sensor

1. Disconnect the sensor harness; then remove the sen-
sor from the exhaust pipe.
2. Suspend the sensor (only up to the threads) in a con-
tainer filled with automatic transmission oil; then
slowly heat the oil on a hot plate.
3. Using a fluid thermometer, closely monitor the oil
temperature, and using a digital multimeter with the
leads connected to the sensor leads, observe the
resistance reading.
4. The sensor must read as shown (see chart).
° F ° C
77
122
212 100
302 150
Coolant Temperature Sensor
1. Disconnect the coolant temperature sensor wiring
harness from the main harness.
2. Test the resistance between the two leads from the
sensor.
3. Compare the resistance reading to the Voltage/Resis-
tance Chart - Coolant Temperature in this section.
Air Temperature Sensor
 NOTE: The component temperature must be known
before conducting this test. Allow the engine to reach
room temperature.
1. Disconnect the wiring harness from the air tempera-
ture sensor.
2. Test the sensor connector. Compare with the Voltage/
Resistance Chart - Air Temperature in this section.
 NOTE: The air temperature sensor utilizes a therm-
istor. Resistance will change as temperature varies.
1100 cc

Magneto Coil

1. Disconnect the white three-yellow-wire connector.
2. Connect the red meter lead to one yellow wire; then
connect the black meter lead to another yellow wire
(a total of three tests).
3. Resistance must be 0.2-0.4 ohm.
ohms
25 219.6
50 238.5
275.9
312.7
5-9
5