So I was riding my gpr 125 and got to bout 7000 revs and it flew to 12000 ans kept going even tho I as coing up to a corner and I stopped twisting throttle so I killed the bike pulled over let it chill for a few turns it on it just fle to 12000 uncontrollably the bike hadn't been run for a while atleast 6 month I haven't looked at anything but the rev cable which seem fine anyone now what could be the cause of this and is it a common fault would appreciate as much help as possible I am limited on motorbike knowledge and am trying to learn to diy my motorbikes to save money and am keen to get started with this lol

Motorcycles - Derbi