Who does automatic tensioner works in scooter?

Title. I need to tight something in every service how does its works? I mean to this part i need tight something in the hole inside?

https://www.google.com/search?q=gy6...id-xiaomi-rev1&prmd=isvn#imgrc=JzWwQtMzpxPiVM

 

Hello Yoni, you want to buy chain tensioner? What scooter do you have.

 

I have kymco downtown 350 .no i want to know what lifter tensioner are ? And if faulty tensioner can cause my scooter losse power

 

It would most likely lose power if not tensioned properly. You need correct tool to tighten the tension. I don't know personally what lifter tensioner for downtown is. Good luck my friend.

 

It would be very noisy if that was faulty, you would hear the timing chain rattling. "tatatatatataa" sound...

 

No i dont hear strange sound.. but.. i feel my scooter loose power its not acceloratie like before and its feels like his loose his tourqe service done 1000 km oil change oil filter and airfilter all done 100% alright

 

Drive belt or rollers maybe?