70cc kit and 28mm carb?

Thanks. I'm a complete newbie to all this. I've just bought a cheap Gilera DNA 50cc derestricted. Its got a sport exhaust, couldn't tell you what make it is. Everything else looks standard and I'm wondering if this is the root of the problems I'm having so thought I'd stick some mods on to deal with the derestrictions. The problems I'm having is, when i twist the throttle it has to go up quite a few rpms before the wheel even starts to turn. Can anyone advise on this?

So was thinking of Polini sport or corsa 70cc Kit? And thanks to this forum - a 17.5/19 carb.... is there anything else I should think about fitting? Also would shops fit it for me?

 

Same as my ped mate, needs upjetting and maybe lighter rollers or different clutch spring

 

Run a 21mm and its spot on. Good power increase and it doesnt overfuel. Been clocked at 70mph

 

not going to lie 28mm is too much for anything under a race kit.