Hi Thanks very much. Yes I picked that up from the text and had had a look at the links you post. The Flying S is a newish model which came fitted with TTS but I think I will reset to default and start again with it as I probably did several changes at once instead of checking them out. I have done 5 locos now, a class 57, class 66, FS, Tornado, City of Liverpool and the limited edition Sir Tom 66, and they are all running so much better. Only really the FS however the Tornado is interesting in that it runs so smoothly and is now quite happy to just go around and around however I don't seem to be able to increase the speed which is slower than it was but certainly smoother. I don't seem to be able to see anything that relates to limiting the speed so not sure which CV would increase it. thanks Malcolm