The bike was occasionally finding neutral between 1st and second while on the move and had also popped into neutral from second (no help from me). The clutch also sounded a little more rattley at idle until the lever was pulled in. The clutch lever seemed to be working OK and I checked the chain slack (in spec) and changed the oil ( used to work on the GPX250 when it started getting false neutrals). Then I discovered a return spring (pictured) had broken. The clutch lever still moved out when released but there must have been just a little bit of engagement to upset the bike every so often. I've bent the spring to get it to work again until a replacement arrives.