Just to give my 2 bits, the slack in the belt measuring from a straight edge is 1 1/8" any more than that and it is too slack. If your belt is as loose as you say it is check your motor mounts, make sure there are no broken lugs (it has been a problem according to a local P mechanic) or loose mounting bolts. As a previous lister mentioned the distance between the drive and driven clutch centres is 10" + .1/ -.05.
As for the creeping problem the route cause in <u>most</u> cases is a worn teflon shim that controls the end float of the EBS clutch. This can be checked by removing the belt and sliding the EBS sprag clutch back and forth and if seems to be excessive (difficult to measure) then the spacing washer is worn and in need of replacement. The Teflon washer is 0.030" stock and in need of replacement at 0.025".
Hope this is of some help. If you do change this shim make sure you upgrade it to the steel replacement. Some dealers are still selling the Teflon shims, I assume to continue making easy money.

 

Just thought of something. Your secondary could be stuck open. Due to crap caught in it or a bad spring. Is the belt resting inside the pulley or is an 1/8 of an inch sticking up over the secondary pulley?

 

If you have EBS, the belt should never really get 'loose'.
If you DON"T have EBS, almost getting the belt to touch between the pulleys isn't too bad, the belt may be worn narrow.
Look at the rear pulley. The belt should just barely be above the top surface of the pulley halves. If not, the rear pulley is stuck open, or the belt is narrowed from wear.
Check the front pulley for smooth operation. A bad bushing, or grooved weight will cause the same problems.

 

hey guys,
I just joined and was wondering if anyone knows why when i put a new belt on my 800 sportsman it seems loose on the rear pulley and rubs the gaurd. Any info would be greatly appreciated.[img]i/expressions/face-icon-small-confused.gif[/img]

 

got a pic?

 

Stupid question, but are you sure that you have the right belt for your machine?