end of my rope, a lot of replacements, no gain

[titfortot]

got a 2009 150cc zhejiang magnum 150cc (knock off chinese scoot, with the problems to prove it)

replaced:
CDI/ ignition coil
cylinder head
spark plug (used to burn through them, was fixed after replacing cdi and coil)

adjusted the valves: .005 exhaust and .005 intake (have adjusted from .004 for both as well, they were extremely tight when i first went to adjust)

cleaned air filter which was covered in oil that was shooting from breather tube (fixed this by plugging up excess air box holes and just leaving drain and breather)

ive also cleaned the interior of the cvt, which was covered in dust, also sanded and put boric acid on pads and bell, which helped with the surging rpm problem i was having.

and nooooow, no matter how much i adjust the air/mixture and idle screw, it idles roughly (granted it does idle, when the air/mixture screw is about 5 turns out and the idle screw is down so far it nearly makes the back wheel spin) as well as doesnt want to go past 5,000 rpm's.

could this just be bad valve/air fuel mixture/idle adjustments i should just keep tinkering with? could it be as simple as up-jetting? what am i missing here?