I just bought my first RZR two days ago and it needs the primary clutch rebuilt. When I picked it up, it was at a shop getting serviced and the owner of the shop informed me it needed the primary clutch rebuilt. He said its faster and way easier to just replace the whole thing instead of rebuilding my current one. It is a 2008 RZR 800 for reference. He also told me if you replace the 08 primary clutch with the primary off a 2009 RZR S, it will add about 10mph to your top speed. I am trying to find out if that is true or not before I go out and replace mine. Any input would be awesome.