I need two Yamaha O2 oxygen sensors, 65L-8592A-01-00

I'm looking for two Yamaha O2 oxygen sensors, 65L-8592A-01-00 for my twin Yamaha 250hp 1997 OX66. Seesm to be mixing the gas wrong and realy fouling the plugs weekly.

Does anyone know where I can get them wholesale, or cheaper? They are $222.40 each retail.

Thanks!