Hope you don’t mind me having a go at this one! PLEASE interject anyone who has other advice (always willing to learn).
Some time back on my running TS 250/1 I noticed a gear box 9clutch side oil leak so I thought to myself renew the clutch side casing seal so I bought a couple of thick ones from Martin (Burwins) and set about the renewal… only thing is that I took the kick start arm off (silly me)…
Now the point is that I had to reassemble the kickstart before replacing the clutch-side cover back with the new seal.
I would inspect the spring to make sure it is ok and located as it should be.
Others will no doubt be able to illuminate on names of parts. You will need a vice with soft teeth and you need to place the shaft in the vice and turn the casing 1 and a quarter turns and replace the kick start arm and cotter pin.
There is a video on you tube (about 59 mins) in English dubbed which shows you how to!!!
It sounds to me that the spring is too loose The link is: https://www.youtube.com/watch?v=6ptXHE2i0x0 Note it is an ETZ but the principal is the same. Just been on the site and the video is a but stop / start but might be my internet connection