So the newly aquired 400 history being unknown I decided to take a peek at the variator and clutch to see what was in there.
I had bought a new spring for the clutch and a new belt. stopped short of buying anything else as I wanted to see what was fitted. First thing was the variator, oh dear, seems like something went wrong in there resulting in me ordering a new variator.
Not sure what has happened, bike seemed to be running OK no major problems but clearly this one could not go back into service.
Good news is the clutch looks fine. So I'll give it all a good clean out and reassemble the clutch with the new spring fit the Dr Pulley variator when it arrives and box it back up with the new belt in place, good job I checked it.