Here is a step by step for some driven pulley maintenance.
1. First of all you should have a 39mm socket for this process. The nut can be removed with a adjustable wrench but if you have the socket this will be easier. My socket was about $15 tax included. I figure we don't need to cover how to remove the clutch/pulley assembly as this is covered elsewhere.
2. Once you have the assembly off of the scooter sit on something like a stool or chair with the pulley on the floor. get your socket ready on the handle and in reach. place both feet on the either side of the clutch with the nut facing up of course. Put even pressure on the pulley with your feet to relieve the tension of the spring against the 39mm nut. hold your feet down and remove the nut. then carefully and slowly release your feet.
3. Now slide the spring off the pulley and head to the bench.
4. Slide a screwdriver under the flange and gently pry up the collar.
5. Remove the small rollers and lay them aside. They will need to be cleaned re-greased and re-installed after the other cleaning on the rest of the assembly.
6. Clean all of the inside sliding surfaces clean with a rag then with a rag soaked in something like carb cleaner or some brake clean.
7. You need some grease that is tacky and won't melt too much with heat. I use synthetic brake lubricant it works very well for this kind of thing as its very much like the pins on automotive brake calipers.
Now re-grease the inside of the outer plulley making sure the fill the little groove with grease and smear a little grease on the the two seals.8. Put the two pulley halves back together and put the pins and or rollers thave been greased back in their little holes. Pack more grease in each roller slot.
9. Reinstall the spring seat/collar
10. Pull the two pulley halves apart a bit and clean all of the surfaces that contact the belt with some carb cleaner or brake clean and a rag.
11. Now to reassemble. Put the spring back on and follow steps 1 and 2 but in reverse. Put the clutch over the spring and line up the hole. Push down with your feet to compress the spring. Now make sure to carefully thread the but by hand as its so very easy to cross thread the nut even by hand. Carefully tightent the but by hand with the socket wrench.
Now enjoy proper variation of the varaitor
