I have a CB200T (US) that had been sitting for a while. I've got it running, but when it starts it revs real high and then dies. The left carb seems to be running out of fuel. Carbs have been cleaned really good and adjusted. Could this be the float? Something else?
I think it could be the float, just give some petrol in a vessel and dive the float in the petrol.
If you see bubbles coming up you know the float is probably leaking.
Otherwise it could be that the flaot needle doesnt tight completly, in that case you could try to seat it with some griding paste.