Aerox 70cc jet size?

Hello guys.I have same problem.I have tuning on my aerox:
70cc kit stage 6
sport pipe
carb dellorto 17.5 --with main jet 90m

Before i ride without filter (i dont have filter when i buy this moped ).

I buy and put the new sport filter engine start but don't run from place.Get out filter an scooter fly . Where is the problem ??Main jet??Any ideas?
I test with 75 main jet moped run but only 35km/h. With 90 jet start but don run with 75 run very slow .what is the good jet size for this modifications?

maybe wrong ecxaust,, wich Cilinder do you have ? Racing or streetrace , with the wrong ecxaust the scooter never come into the Powerband.

Vario Rolls OK? the right Pressure spring ?(clutch) ..Pullsprings OK ? right Collor.

stage 6 street race is my cylinder