Speedfight 2 problems with fuel consumption and emissions?

Hello, I have a Speedfight 2, the year of manufacture must be 2002.

The scooter is completely original, only the throttle ring in the variator is missing.

Since this has been removed, the scooter consumes more, but in my opinion the consumption was much too high even when throttled (6-7 liters per 120 km with normal driving).
In addition, the oil consumption is far too high. I think there is something wrong with the oil pump, which is probably why the scooter is emitting so much blue smoke from the exhaust.
My first question is, would it be wise to convert the scooter to a mixture and run it at 1:50?

The other question I have is whether I should make any changes to the carburetor, particularly regarding the throttle control, since it could also be the fuel-air mixture that's far too rich. This could partly explain the high fuel consumption.

I don't really know where or how to start…

Thank you for all the answers 🙂