clutch issues

I've have a really nice 02 kx 250 thats tits,Theres only one problem,when The engine is warm and i'm costing ,I can pull the clutch in and the motor will not come down to idle( as if i never pulled it it) The bike starts good in gear,but i can still tell that the clutch is still ingauged. I've double checked,cable,pull rod,all the most common things,Whats funny about this is I've got a 98 yz125 that does the same thing,and i've replaced everything thing to do with the clutch(basket,pressure plate ,bearings pull rod, cable,plates) I'm running belray motorcycle gear oil ,I think it's 75-85 weight,I'ts for 2 stroke gear boxes,And in my yz I've tried all kinds of oil and had no luck,any help would be greatly appreciated!!