Happens now and again no pattern to it at first thought it was me ridding the clutch.cable is action is smooth and free.do a gear change and clutch slips let the power off then boot it and it's fine only happens very rarely all I can think is the clutch plate getting jammed up.
could be an oil leak from the gearbox seals, has it been off recently? the clutch cables can stop self-adjusting properly as well, worth a look at that as well
Ok cheers haven't touched gearbox will reset self adjust cable and check ,if it gets worse will drop box will give me the opportunity to replace the reverse idler while it's out.
it may be the clutch is just starting to wear out, if its not been done in the time you've owned it. I would say a new cable is worth trying before the box is dropped. even if its not down to that ideally you want a new one once the new clutch goes in since old cables sometimes dont like it when put on a new clutch. see how you go with it though. If box comes off you'll want to do the pushrod bush and seal plus the input shaft seal to make sure its not going to leak oil any time soon. crank seal might be worth doing too, see how it looks when box removed. if reverse gear is damaged then definitely worth removing the box for a checkover or replacement, Martin Emment of gas n gears can do all the work for you