Speedfight tuning advice

Got a speedfight 2 50 ac

With corsa racing clutch, polini variator and a stage 6 exhaust it only manages 40 and I am 17 in about 2 weeks so it's time for a kit?

But what kit should I get? Also what other parts do I need with the kit?

Thanks nathan

 

with any kit, you need to make sure you do the jetting right. cant help more than that

 

Need to know what best kit is for speedfight 2 ac if anyone knows