Misfire in the hole!

[XenoMorphicRex]

As the title of this thread humorously says. I dealing with an odd occurrence of My 2008 CF Moto Fashion 250-T

I've owned this Scooter For 2 years. Bought it from a Local collision shop owner who had, bought it for his wife. She put about 900 miles on it, and then it sat in the shop for 3 yrs. collecting dust. When I saw it, I bought site on seen for $1100.00 USD. I've lovingly Maintained this sweet little scoot, I even nicknamed Her Matilda, Since I bought her, the odometer has reached just north of 3500 Miles, with few problems, until recently that is.

Anyway, The issue is that at Idle, and at low speeds (25Mph or less) she runs buttery smooth, but at higher speeds she starts Misfiring, and starts jerking and bucking, and sputtering, Sometimes even stalling.

What I've done to my scoot since getting it:

(1) 32mm Performance Carb
(2) K&N Pod Filter (Stock Air box removed and junked) "No tuned Pipe yet"
(3) replaced Melted Junction Box (Don't Ask how that happened)
(4) New Tires, Vacuum, Coolant, Fuel Lines with filter
(5) Oil Changes Every 1000 Miles (I know "Overkill, read my Signature") I use Royal Purple 10w 40 full synthetic.
(6) Final drive lube changed with "Lucas Oil Gear lube" once since purchase
(7) New front 4 Piston Brake caliper, disc, and Pads. New Rear Brake Shoes
(8) Laid it down Once (rookie Mistake)
(9) CDI upgrade (No rev limiter)
(10) Performance Coil, and NGK iridium sparkplug (Hotter plug)


Anyway, aside from some Cosmetic Damage, It's been super reliable (Unusual for a Chinese scooter in my experience) I've checked the usual suspects for hesitation and misfires, CDI is find, Ignition Coil is fine, put a new Sparkplug in it. Checked Oil levels, and Gaskets, seals, Timing chain, Valve lash, and seats. and Compression tested it. As far as I can tell, There should be absolutely no reason for the problems I've been having at Higher speeds.

But yet She's been acting like she running lean, or the ignition system have been cutting out or something.

Now I'm a Mechanic by trade, and its also my hobby. So I know a thing or 2 about Engines, But I am thoroughly stumped. Anyone have this issue or have a Solution? I'll answer what questions I can, If I know the Answer. My memory hasn't been all that good these days. (Getting old) So Some things I should know by heart, may slip my mind from time to time.