My raptor has this problem:

When it's been sitting for a week, and i fire it up, i pull in the clutch and click it down ionto 1st. It then jumps foreward. So i let it warm up, and it seems ok, but the clutch seems to "chatter" when it's warming up. Also, when i am riding, i go to start er up, and she jumps foreward a bit this is not normal? I think i may need a new clutch!!!
What clutch should i get for it that will last....? please help dudes!

 

Don't worry, it's normal. The clutch discs get "glued" by the oil because they are at rest for a long time (my dirtbike used to do it all the time). It might go away of you change your oil, but again, it's absolutely no problem, no consequences...
To get rid of it, you can:
-before starting yor quad, put it in gear, pull the clutch, and push it (front or rear doesn't matter) until the the clutch works (it should roll free as long as you keep the clutch engaged...normal)
-you start it in neutral, pull the clutch (sticked so it won't do anything yet), push your quad to have enough speed so you can put first in and not stall. Then just ride around, clutch pulled in. It should be back to normal very fast.

Nothing to worry about anyways.

 

Zorro, thanks a million. I'm going to flush the old oil out and then go with some Yamalube but I will try your suggestions.

Again, thank you.