Turns out it was the tappets, one was holding a valve open all the time! Got it back today, has had a new plug put in aswell, runs soo much smoother but can hear the tappets quite loudly now :/ I was told that the Kymcos use a special version of the GY6 Chinese sh**e 4 stroke engine and they need the tappets re doing every 1000 miles, and this has gone 5000, so was to be expected really!
