Modern Vespa

Hello everyone i just subscribed! I'm working on my fiancee's ET4 125 Leader

I had no compression so i opened up the engine and found a stuck valve which I'm going to remove and clean / replace, but i also found a broken piece in the tensioner and i can't seem to find it anywhere. I will put photos here and i ask you if you can tell me the name or where to find it. Thank you very much.

https://www.sip-scootershop.com/en/product/automatic-decompression-regulation-kubler-racing_KBR10003?usrc=Dekompresor%20et%20125

it's the centrifical counter weight for the decompression on the cam while starting.

some refer to as the decompression level or weight.

here's the part number: PI829134

you should be able to find one used on ebay fairly easy.

I've never seen one break in that manner. impressive.

All right perfect i found a used one on ebay. Could this thing be the reason my valve hit the piston? Or should i look to replace the chain? Thank you