I had noticed a bit of roughness in the primary halves can these be sanded smooth and what causes them to rough up.
Matt
2000 500 Scrambler

 

Do you mean that when you slide the halves against each other, it feels rough rather than sliding smoothly, or are the pulley halves rough where the belt rides? My Clymer's manual says you can use FINE steel wool & solvent to remove any burnt belt residue, leaving the surface as smooth and clean as possible. Be sure to wipe clean all the solvent so the new belt won't slip. Electrical contact cleaner works well for this, and leaves no residue. If the metal of the pulley itself is rough, it might be best to take to the dealer to see what they can do.

 

One more thing, if the roughness IS due to belt residue, it is a sign the belt got so hot the surface actually melted and 'baked' itself to the primary pulley.
Be sure the pulley cover vents are not plugged. The belt uses cool air pumped through these vents to keep things from overheating.

 

Mine blew the second day I rode my 00 Scrambler 500 4x4. The dealer races snowmobiles, and said that excessive heat tears up the belts (I got stuck in mud in 4wd in May, and was rocking it while hitting the throttle). He recommended an aftermarket clutch OR scuff the inside surfaces of the clutch. If you scuff, use a high grit sandpaper (80 or 100) scuff in straight lines tangent to the inside of the clutch pulley. The dealer fixed mine for free since it was within a week, then I scuffed it. It gripped the belt enough to notice. I had trouble getting the front end up (wheelie) before scuffing, but not after, and it worked well enough that I never bought the clutch kit I was going to buy. It's great if you 01 owners get a lifetime warranty.

 

I've had my 350L for almost 9 years and have put 2 new belts on. Both have been since adding the Bi/Tri-Claw mud tires and were caused by towing heavy loads from a standing start in deep mud.

 

When you say High grit do you mean 800 or 1000's as 80 or 100 grit seems a little harsh.
tnxMatt
2000 500 Scrambler

 

Nope, the dealer said 80 or 100 grit. I used 100 grit. 800 or 1000 grit seems to me like it would "polish" the inside of the pulley, and it's probably too light to make a difference. Unfortunately, I haven't had mine long, and I MUST sell it, so I can't comment on belt longevity. However, I got two rides out of the belt before scuffing, and 8 to 10 after. The dealer said heat was the enemy, and you get heat when the belt slips. I'm sure the scuffed pulley will wear the belt faster than if I spent money on an aftermarket clutch kit, but after losing a belt on a ride, my buddies and I with polaris machines all carry spare belts now anyway.