Polaris FST IQ Cruiser Owner's Manual page 146

Track Tension
4. Check for specified slack between the wear surface of the track clip
and the plastic rail slide.
If the track needs adjustment:
5. Loosen the rear idler shaft bolt.
6. Loosen the lock nuts.
7. Tighten or loosen the track adjusting screws as necessary to provide
equal adjustment on both sides of the track.
8. Repeat the measurement on the other side of the track.
NOTE:
Check more frequently when the snowmobile is new.
9. Start the engine and slowly rotate the track at least five revolutions.
Let the track come to a stop (do not apply brakes).
10. Check track alignment (see page 144) and adjust as necessary.
11. Tighten the lock nuts.
12. Tighten the idler shaft bolts. Torque to 35 ft. lbs. (47.5 Nm).
Adjusting
Screw
MAINTENANCE
Idler Shaft
Bolt
Lock
Nut
143