Speedfight 3 Lc

[Danilo2929]

I have problem on sf3.His start is good but after start 40 km/h it slowly develops speed up to 80 what I can change on him
Setup:
Clutch-Malossi Delta System yellow springs
Black central spring
Exhaust-Leo vince tt
Vario-factory
Cylinder-50 ccm
Please help what combination to use on him.
Thanks!