My speedfight 2 100cc is spluttering and has no power?

I've just brought a Speedfight 2,100cc which has been upgraded to a 120cc.I was told by the owner to mix 2stroke at a ratio of 33/1.
When I try to ride it,the bike smokes and will splutter,every so often it will sound normal upto 5k revs and dies again.
There is no power there.

ANY ADVICE PLEASE ?

Upgrades include;
Mallossi 120 kit and variator,
Polini clutch and kevlar belt,
pm tuning gear up kit,
21mm tnt carb,
Doppler s3r pipe,
stage 6 inlet manifold and v reedblock,
hi-per coil,the bike hasnt been ran in since upgrades.