Motorcycle and Scooter appreciation

Sounds like it's burning oil if it's grey/blue smoke. Has it ever done anything like this before? Worst case scenario could be worn rings or valve guides. Could be crap in the carb but you'd expect a good run to clear that.

Have you checked the colour of your plugs? What's the mileage and does it need topping up with oil frequently?

Also try running your finger around the inside of the exhaust just near the end, when it's been sitting for a while. If it's damp and black, you're probably burning oil.