Hulp nodig met Bashan 200

[Mauro1990]

Hello, i had my bashan200 rebuild. she is perfect except the fact that she don't go more than 70km/h .. when i go to 70km/h she looks like the limited bromfiets going 45. and dont go past that. can anyone help me knowing what i can do to change that??
ive put a smaller tandwiel in mijn ketting. ive changed uitlaat, unscrewed the accelerator screw a bit more and she still do that. i use it a lot for passing on highway and so but like that is boring and i think dangerous because i cant really keep uo speed when i need to.
Please someone let me know what to do. Also e didn't change electronica on it but i heard that maybe can be done on the wireing. is that true?
alstublieft.

Met vriendlijk groet,
Mauro Sá