Stock bulb was too dim so I installed a hologen 50/60. This light is also dim, high beam is just dimmer than the low beam should be and the low beam is almost useless. My battery measures 12.3V and all the connections are clean. The other lights seam ok, as they don't draw much power. I have heard that these bikes aren't known for having the brightest lights. Would an aftermarket rectifier solve my problem? If so, any recommendations.
A fully charged battery should give you about 12.7 volts. If your voltage regulator is working, you should see more than that (14 volts ??) at the battery terminals when the engine revs to 3,000 rpm or so.