Zong 250cc needs more grunt

[b44]

So ive finally completed rebuild, bike runs sweet, idles fine, starts fine,
Just a few issues
Its got a flat spot around midrange,
I have to get a huge run up to get up moderate incline
Ill start playing with carb settings
Try gearing it down
Weight reduction etc
I wasn't expecting xr250 performance but i also wasn't expecting to be that gutless,
Any help appreciated
Zs169fmm
Keihin pz27 carb
Frame/ unknown