1986 Ski-Doo Factory Shop Manual, Page 251Get this manual

Section 03 TRANSMISSION Sub-section 02 (DRIVE BELT)
Adjust pulley distance according 0 specification Isee puley distancealignment section 03-05) and measure drive belt deflectionReadjust pulley distance if required, then tighten the nuts, adjust pulley support and lock it

NOTE: The top of the drive belt must be flush with the driven pulley edgeEquany screw or unscrew the three Allen screws to obtain this specific adjustment
Skandic, Skandic R, Formula MXPlus
Adjust pulley distance according to specification (see pulley distancealignment section 03-05), Final drive belt deflection is adjusted with Allen screws located on the outer face of the driven (fixed half) pulleyAdjust belt deflection: :

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives