http://www.partzilla.com/parts/search/Suzuki/ATV/1990/LT250R/CLUTCH+%28MODEL+H-J-K-L-M-N%29/parts.html

I tighten them all down real good. They bottom out or the head tightens down. Part number 10 above. If not I would think they'd back out and cause a nitemare.  My 89 used to kinda act like yours, but it wouldn't kill the engine. I screwed around adjusting the cable for a bit and now I can start it, pull the clutch lever and throw it inta first and the rpms drop like 500, barely noticeable, it its warmed up no drop.