1988 clutch

Well, if I were you I would strip the clutch down and examine the plates and springs. The plates could be gummed up, or more likely worn too far and need replacing. Check the springs' free length against the specs and replace them if they are out of spec. Try a set of springs for a KX250 - thay are longer and stronger (your clutch hand will notice the difference though!). Replace the oil with clean oil of your preference - any 10w - 15w oil without friction modifiers will do the trick. And change it often.

Cheers,
Andrew

Yeah, I would take a look at the clutch plates. While your in there you might as well replace the clutch plates and springs. I have an 88 with the original stock clutch plates and springs. It doesn't slip yet. It just takes a couple minutes to warm up. I've been useing Maxima 80 weight clutch saver tranny oil w/o a problem but I'm switching to Mobil 1 15w-50 or 5w-50 because it's easier to find and may be better.