2003 Polaris ATV Trail Boss 330 Factory Service Manual, Page 125Get this manual
DRIVE CLUTCH SPRING SPECIFICATIONS
The drive clutch spring has two primary functions: 1To control clutch engagement RPMThe springs which have higher rate when the clutch is in neutral will increase clutch engagement RPM2To control the rate at which the drive belt moves upward in the drive clutch sheavesThis is referred to as drive clutch upshiftThere are other components which control upshift, but the spring is one of the primary components in insuring optimum performanceIt is very important that the spring is of the correct design and is in good conditionCAUTION: Never shim drive clutch spring to increase its compression rateThis may result in complete stacking of the coils and subsequent clutch cover failureThe drive clutch spring is one of the most critical components of the PVT systemIt is also one of the easiest to serviceDue to the severe stress the spring is subject to during operation, it should always be inspected for tolerance limits during any clutch operation diagnosis or repairNEUTRAL 300