Hi Steve, revisited the carb today after your suggestion and found a completely blocked idle jet. I hadn't seen it before and where as the other jets were gummed up with oil from the evaporated petrol, this was solid. I managed to unblock it with a strand of wire from an old brake cable. Needless to say its running a lot better! I also changed the trans oil, I put 650 ml (putoline light gear oil) in as suggested by a gas gas guy on you tube. Do you know if that's correct only I drained 800ml approx?
Regards
Mark