Just for interest sake (cos its luckily not necessary for me to do this time) how do you adjust the tension on the throttle return cable on the carb side when the carbs are on the bike. It has a little lock nut and its all so hidden between the motor and the frame I don't believe it can be adjusted with the carbs on the bike or is their some other tool or trick?

Ive just had the carbs of my NC30, its easier to do by taking the tank off and the airbox (from my experience). The top cable that sits in the holder is the accelerating cable and the bottom cable is the decelerating cable. It is possible to do with the carbs on the bike with the tank and airbox off, just a bit fiddly with a 10mm spanner to adjust the lock nuts and adjusters, you may have to undo the accelerating cable and remove it out the holder to get at the decelerating cable. If you have a haynes manual for it they do explain a bit about it in there, hope this is a bit helpful.

Regards......Cal

Ah ha removing the top cable would be a good idea - thanks