Whats Up With The Stiff Clutch

[ROOFCOCK]

i recently put a new vitos clutch kit in my shee. at first it worked good just riding around the yard and such but as it got hot it seemed to get harder to pull. so with a little adjustment it got better. when i got to go riding it was fine at first but after shee got hot it was stiff as hell, and it seemed like it would get better if i kept the rrrr's up. what i mean by this is if i rev it up or get hard on the throttle it would get easier to pull in at the lever. also once it gets hot it wont start in gear with out kicking the hell out of it, if at all. anyone had this problem. is my basket wasted and i didn't notice. the bike is a 92 i took down to the frame and made it new with love and ebay. the first top end job was done about 10 hrs of riding ago so to speak and inside the engine and cylinders were perfect so i really don't think its the basket because i bought the bike from a guy who never rode it, and everything was stock until i got a hold of it even the brake pads.i bought it in 96 and i only have about $700 in it before my mods(bone bone stock)so it is far from abused any ideas. thanks