Just to update. Finally got to work on the bike on Sunday. The old spark plug was very worn (electrodes worn away), and covered in sooty black stuff. Not even sure that it was the right sort because it had a different number to the new one (which is right!).

I checked the air filters as well which looked fine. Put the tank back on and hey presto, life!

Will have to keep an eye on it to see if there is a more serious underlying problem, but at least its now running. I'll probably clean the carb out at some point anyway, thanks for the suggestions! :mchappy:

well, the sparkplug is always the first thing to check... NGK DPR8EA-9


Have fun riding!
Vando ;)