There are multiple reasons - plates, basket, stack height, master cylinder etc. In order to know how to fix it, you have to identify the problem. Best bet is to strip it down and assess the whole system and repair/replace/adjust whatever you find.
Great I'll pull the plates out tonight to see what sort of coverage I have what thickness should I be looking at an the plates and what are a good plate to fit
I recommend that you invest in a Workshop Manual - these are available cheap on e-bay and have the answers to all your questions.
If you are using the standard Clutch master cylinder then I always bleed the master cylinder if I have clutch drag or disengagement issues, as this is bit of a weak point on the bikes. but on the positive side, all you need is a 6mm spanner and a Philips screwdriver and it takes 2 mins. but those plates don't look the best..
