your primary and/or secondary clutch cylinder is leaking. Better have them replaced. =) can't think of any other cause.

did you check the resevoir? Check if nababawasan. check mo ren inside, dun sa pedal mismo if may tagas...mahirap yang ganyan. i was on the road nung lumusot clutch ko and 2x na nangyari. i was able to get it to run but only for about a km or so tapos d na umakyat tlaga.