HELP!!!!! Aerox yq50

So my 70cc aerox stopped working I assumed it blew up beacuse it had a slight graze on the side so i bought a 17mm carb (downsizing from 21mm for cheaper fuel)
And a tnt 50cc barrel piston and head and to my suprise the bike has good ish compression and isnt firing up still i have a br8hs plug as the br9hs was hiting the piston.

the bike has
Spark
Compression
Fuel

My only guess would have to be the ignition timing or stator any help would be appreciated as ive put nearly £3000 into this aerox

 

Have you still got the original stator on there, and also do you know how to adjust the ignition timing?

 

The timing won't really go out on these...
How much compression is there?

 

If it's a 2T, ignition timing is fixed and controlled by the cdi, non adjustable.
4T has timing marks on the flywheel, valves to adjust.
As scuba says, what is the compression reading?

 

i dont have a compression gauge but i can tell it needs to be higher how would i go about that