Thanks fellas
I collected the bike on Saturday and it didn't do it.
Rode it for the first time since then today. All good for the first 70 -80 miles then I noticed a couple of times going round a junction it started to feel like it was missing. By the time I'd done 120 miles it was doing it every time I came to a stop or walking pace traffic. Couple of times it cut out altogether.
Just checked the TPS and it was reading 10k with a closed throttle. Adjusted it to 5k now. Is that not ideal?
Checked the Exup and the servo is certainly moving. Will have to get on the floor to check t'other end.
Maybe it's crap or water in the fuel so I've given it a dose of Pro-FST.
Nothing added under the seat and the air intake doesn't have any mice or other creatures nesting in it.