2004 Ski-Doo REV Series Factory Service Manual, Page 255Get this manual
Section 06 TRANSMISSION Subsection 04 (PULLEY DISTANCE AND ALIGNMENT)
Measuring Procedure
Using Straight Bar Always measure distances and from the farther straight bar side (including its thickness to the fixed half edge)The distance must exceed distance to compensate for the twist due to the engine torque
Drive Belt Deflection
NOTE: When pulley distance and alignment are adjusted to specifications, refer to DRIVE BELT to adjust drive belt deflectionCAUTION: This section deals mainly with adjustment proceduresFor complete assembly requirements, refer to the proper ENGINE or TRANSMISSION installation section