Carburetor

[tch]

Hello all.  I'm looking for a Mikuni left-side carburetor (the outermost one under your left leg while sitting on the bike) for a 1987 Yamaha YX600 Radian.  The information on the carburetor body is: 1UJ DO F664.  It's been discontinued and is no longer available from Yamaha.  Any tips shall be appreciated.  Thanks, T. C. Howery VMOA #662.