My buttons on my machine are a little worn on my 2000 xc 700 , what effect on performance would it have on my machine ?

more friction,slower to up shift.plus belt width adjustment will change slightly,they cost next to nothing,easy to change,i ussally change them 3 times a year,and if you run a steeper helix then the stock 36, the steeper the helix ,the faster the buttons wear.

would this account for a loss in rpms or top speed ? Im curious xc specila how do you like the slp pipe on your machine did you have to play alot with the jetting would my epi kit work with the pipe ? thanks

actually that would increase rpm,due to clucths not shifting down fast,the slp pipe works good,not sure exactly how much improvement,it seems i do to many changes at once,slp 3-6000 ft heads with the pipe,
could stat with a 02 700xcsp,beat a 00 mxz 700
as far as your kit? depends what it constsists of.jet once with a tempa flow and leave it

The super slippery buttons are money well spent also. great lil upgrade for a few bucks more.