Graham,from experience do the TPS first,I thought the same as you when my Wee started playing up at low throttle openings.I set mine a low as possible and it transformed the bike,the throttle balance was only a whisker out.Good luck with the TPS,it needs a great deal of patience as you only have to breath on the adjustment and it goes all over the place.I set mine as low as possible,from memory 1700rpm was as low as I could get it.Not sure what the factory setting is,someone will come back and tell me no doubt.