I don't own a busa, but I sat on three 2006's at the motorcycle show yesterday. My favorite was the white one, but I also liked the blue one. My CBR has a hydraulic clutch so I'm kinda familiar with 'em. Fluid isn't escaping, but air is getting in? How is the gasket on the master cylinder cover? How about the copper washers between the banjo fitting and the slave cylinder? Because it's so cheap, I would replace the bleeder. Maybe it was cranked down too much. If you have a speed-bleeder, I would replace it, I don't trust them.