Bike will run, but won't idle, hard to start.

Lets start from the beginning...
I have a 2004 Suzuki AY50 Kantana LC. It has been bogging really badly due to an air leak on the inlet manifold - fixed today with a new O-ring/gasket, all sorted. Now its a real struggle to start, It's got a new plug and the carb has been cleaned, we've adjusted the needle, mixture screw and tick over. Once started it all revs up fine but as soon as you let of the throttle it dies. Trying to start it again is a nightmare. It has a Technigas Next-R Full Pipe fitted by previous owner. It seems to be starving of fuel? The plug is dry as a bone, but is black - running too rich? Perhaps the carb has not been jetted correctly? What size jet should be used?

 

All fixed now, blocked vacuum fuel pump was causing the problem, thanks for reply.