1989 Ski-Doo Repair Manual, Page 347Get this manual
Section 03 TRANSM ISSION Sub-section 08 (GEARBOX)
ADJUSTMENT
56, Chain tensioner
Rotate driven pulley forward so that true deflection can be takenRemove rubber plug and check chain tension
4 to mm (5 137 in to 913 in) defler.tion
ADOS 003 017
To adjust, loosen lock nut and fully tighten adjuster screw by hand then back off to obtainmm (532 in9132 in) deflectionTighten lock nut and recheck chain tension