Arctic Cat Sno Pro 120 Service Manual page 239

8. If the TPS is within the prescribed specification, dis-
connect the adjustment tool harness from the TPS.
Connect the snowmobile TPS harness to the TPS.
 NOTE: Before installing the TPS harness connector,
apply dielectric grease to the connector pins.
ADJUSTING TPS (500/800 cc)
 NOTE: Adjusting the TPS is for out of warranty
snowmobiles only.
 NOTE: It is important that the throttle shaft is in the
completely closed position for this procedure.
1. Disconnect the throttle cable/control arm from the
throttle shaft.
2. Rotate the idle screw counterclockwise until it no
longer contacts the throttle shaft stop. The throttle
shaft should now be completely closed. Open the
throttle shaft by hand and release it, allowing the
shaft to gently snap closed several times.
3. Disconnect the TPS wiring harness from the TPS;
then using Throttle Position Sensor (TPS) Adjust-
ment Tool, connect the appropriate wiring harness to
the TPS. Connect the red and black digital voltmeter
leads to the white and black jacks of the TPS adjust-
ment tool.
4. While observing the digital voltmeter, slowly rotate
the sensor until the Full-Closed specification is
observed on the LCD of the multimeter. While hold-
ing the sensor in this position, tighten the two screws
which secure the sensor to the throttle body securely.
5. Gently snap the throttle open and closed several
times to check the TPS voltage. If it has changed
from the Full-Closed specification, loosen the two
screws which secure the sensor and make necessary
adjustments.
6. With the full-closed position set to specification,
rotate the idle screw clockwise until it contacts the
throttle shaft stop. Using the digital multimeter and
test harness, rotate the idle screw inward until the
Idle specification is observed.
 NOTE: Rotate the idle screw past the recommended
voltage specification by two or three volts; then
rotate the idle screw counterclockwise to the correct
idle position voltage.
7. With the idle position set to specification, slowly
compress the throttle lever to the full-open position.
The full-open specification should be observed. Gen-
tly snap the throttle lever open and closed several
times and note if the reading remains within the
specification.
 NOTE: If, after adjusting the Throttle Position Sen-
sor to the IDLE specification, the FULL-OPEN is less
than the specified voltage, recheck the FULL-
CLOSED setting. If the FULL-CLOSED setting is cor-
rect, replace the sensor.
Engine TPS TOOL (DC VOLTS)
500 cc Full-Closed 0.412-0.414
Idle 0.710-0.818
Full-Open 3.472-4.048
800 cc Full-Closed 0.412-0.414
Idle 0.646-0.754
Full-Open 3.472-4.485
REPLACING TPS (500/800 cc)
 NOTE: Replacing the TPS is for out of warranty
snowmobiles only.
Removing
1. On the 800 cc, remove the expansion chamber and
resonator.
2. Rotate the idle screw counterclockwise until it no
longer contacts the throttle shaft stop. The throttle
shaft should now be completely closed.
3. Disconnect the TPS wiring harness from the TPS;
then noting the position of the TPS, remove the two
screws securing the TPS to the throttle body and
remove the sensor.
Installing
1. Apply a light film of silicone grease to the O-ring.
Install the O-ring into the groove.
2. Install the new TPS onto the throttle shaft by align-
ing the "flats" on the throttle shaft cam with the
"flats" on the sensor; then rotate the sensor until
properly positioned on the throttle body.
ANALYZER TOOL
(DC VOLTS)
0.710-0.818
3.470-4.046
DIAGNOSTIC TOOL
3.99° -6.66°
74.97°-89.37°
5
MS399
MS400A
5-5