i got rid of the weak 6.xx inch headlight that was on my xs400 and put in a 7-inch sealed halogen (45watts i think).
the original headlamp is too weak to light up a road, and is a very dark yellow - i hated it
I opened up the headlight housing, cut out the 2 mounting tabs that connect to the inner rim of the original headlight, duct taped a small piece of rubber in their place, and stuffed an off-the-shelf 7-inch in there. It made a huge difference, well worth the $13 i paid for the headlight