[JonyRR]

DONT MESS WITH THE THROTTLE STOP SCREW! wait until you feel comfortable moving the tps body itself.
Obtain, if you already haven't done so, the rob lentini '0=0' article; read it until you understand it and then follow the procedure exactly. 330MV is pretty 'lean'. You COULD try disconnecting the 02 sensor and pulling the CCP to richen 'er up some (just pulling the CCP OR disconnecting the 02 sensor at the harness plug under the tank should do the trick).
Muck about with the physical throttle body reference stop screw on the LH throttle body at your peril.
I just did this again as a check in my driveway last evening. TPS=390MV at rest, BBS's synched at roughly 1.5 turns and a mechanical synch at 3K RPM hot, and she runs sweet with no backfire, hesitation or stalling at idle and pulls cleanly with no untoward foolishness regardless of rpm. If you did the measurement correctly, 330MV is tooo friggin' lean, man, specially w/ a pipe, filter and induct.
Does your scoot ever stall at idle when you let the clutch out with little throttle?