Nice bike👍, I also have a benelli 250 2c for a few months now and still updating it a little by little. I wondered what fuel oil ratio you use?, the previous owner adviced me 20:1 but i use now 30:1 and i think the motor likes it a bit better.
30.1 is still very rich in my opinion. I mix 40.1 on all my 2 strokes. 20 and 30 are ratios from back in the day with bad oils. Todays oils are much better and can be ran a bit less. I'm using castrol (cant remember which one though) and mix 40.1