I wonder if somehow the instance of these rotting fuel lines (in the tank) is caused by the scooter being ridden so little - which means that fresh fuel is so rarely added to the tank as the years go by.
The scooters with this problem are several years old - and have passed relatively few miles for their age.
Maybe i'm wrong to see a connection?
My LIKE200i was manufactured in 2012 and has 19,000+ miles on it - BUT I replaced the Kymco fuel pump and fuel line one year after buying the scooter....so my scooter can't be used as an example.
If I had an older LIKE200i that had been ridden relatively little - and started running poorly - I'd certainly take a look in the tank to see the condition of that little fuel line!
Stig