Need help before I set it on fire

Hi guys but a non running led Moto echo 50cc upto now it’s had new crank new piston and full top end new variator with 4g rollers new clutch carb fully cleaned but it just doesn’t want to pull dead slow at setting off and crawls to 20mph that’s it ive no idea what else to look at I’m stumped now any idea s

 

Hi mate it’s got one of the I assume racing cdi and coil on both are orange they was already on it it just seems to not really want to Rev it’s not crisp just labours it’s self the wiring to cdi seems a bit suspect but I’ve nothing to compare it too and can’t find any wiring diagrams

 

Correct length/width drive belt?
Clutch springs too weak?
Or torsion spring too weak?