Sir jeg, the difference between the standard round airfilter and my Piped KN filter is the air restriction, im just thinking, out of curiosity, what if i put some layers of cylindrical foams to cover the kN filter this will restrict airflow simulating the original airbox...just a thought. ... You think it might work? I mean its a trial an error.

So, with the siamesed cast-iron stock intake/exhaust manifold, that should not be a problem with icing.
Looking at the table Jed did post of the 3 needles, they are almost identical, except for one would be a bit richer in higher rpms and the other leaner. But that should only affect emissions at higher rpms, and performance very little.

I am back to suspecting the throttle shaft or the intake snorkel.

Tony asked about whether the shaft holes in the carb body might be worn as well as the shaft. From my reading, I'd say yes, probably. I have read that installing bushing is part of the solution, but that would require machining and line-boring to make sure the new holes are aligned and the shaft does not bind.  Translation: a machine shop is needed (for many of us).

Tony: if you can rattle the shaft, feeling slop between the holes and the shaft, then it is significantly worn. It does not take much to mess up performance. An old HS4 I have is slightly wobbly and was giving me problems. I'd suggest rebuilt one from our host.

Before you plunk down $$ for a new carb, try removing the snorkel and putting the stock air cleaner back on.When you remove the snorkel, make sure it was not blocking any of the 2 upper holes shown by the gasket #12 in the attached image. These provide internal breathing for the carb and it won't work properly if they are blocked.

The next issue is that the flow of air into the carb mouth must be very free-flowing without turbulence. Your snorkel from the K&N filter up toward the carb looks like it should be OK, and should provide smooth flow, but when it gets to the carb, there appears to be a dead-end pocket where the crankcase vent hose is attached, and then more internal space beyond that. That is a huge cavity that would produce eddies bad air currents that would really mess up the air flow. From my reading, there needs to be a very smooth, gentle elbow bend from the snorkel to the carb mouth, and even a smooth elbow here can cause eddies and problems.  The length of the tube leading to the carb mouth can also mess up the flow, especially at higher rpm. In other words, even though you put a lot of work into is, and it looks sharp (I like how it looks) it may be the cause of your lack of power a higher rpms. My engine has a cone filter right on the carb, and on full acceleration it allows a lot of induction noise (engine roar). I have thought about making a snorkel like yours, but haven't done anything about it because I don't want to compromise the power I have. You may see them on turbo cars etc. but the airflow problem doesn't matter on a turbo because it is pressurizing the intake system and the impeller cancels out any turbulence problems.

Testing how to post pics...

update:   So i installed new sparkplugs (gapped to 25k's) and sparkplug wires, this afternoon, i notice right away that the rpm went up,, it idle at 1200, i adjust the idle screw to 1000 rpm then i checked the ign timing, the timing went up to 15 degrees, so i adjusted it back to 10degress.(factory)  Runs more powerful now.(feels like 1275)
but I still need to attend to that worn throt $haft i know.

On another topic: 
i lifted mini today on a jack to check the balljoint, i noticed that the cone is kinda slanted, i tried to hold the cone and it is moving, i suspect it got dislodged from the donut, question is , is it easy to fuse it back to the donut? How??  Thanks...

no wondet i feel too much vibration on that side of the wheel.

Sir mal, i did the timing this aftenoon and i tried to rev it, then the white dot advances to waaay over past the teeth, so i dont know really what number it got on advance.