1971-1973 Arctic Cat Snowmobiles Factory Service Manual, Page 169Get this manual
SUSPENSION 26Position the dropcase and dropcase gasket to the dropcase mount; secure in place with three rubber washers and thumbscrews
Observe the eccentric bearing housing and determine if the shaft is behind or ahead of centerApply thumb pressure to the eccentric in the proper direction; shaft will raise and increase tension as pressure is increasedNOTE: If bolts contact the eccentric slide, remove and install in an available holeFor snowmobile usage, the drive chain should be run with minimum amount of slack to insure optimum performanceProper chain deflection is quarter of an inch at midspan of the chainInsure chain is in alignment with both sprockets