Most of our bikes have the headlight circuit flowing through the switch. That means the power delivery to the bulb is subject to the limits of the wiring and connections in the switch. Increase the power of the bulb and you exceed the wiring in the switch... ultimately frying it... and no lights!
Wanting to increase light in advance of the ButtBurner 1,500 ... I've been looking at all options. Without going into a dissertation
, all options start with taking the switch out of the direct line of current flow via a relays. You boost the light production of a fully stock bulb by delivering uncorrupted power from the battery.
Secondly, the optics of our headlights are designed for the characteristics of the factory bulb. Mine is halogen.
So, now on the K, I have the easternbeaver H4 relay kit installed. http://www.easternbeaver.com/Main/main.html
With the healight switch protected... I then installed an 80/100W bulb (NAPA off-road under $10) and huge improvement happened.
Since the light source (halogen bulb) matches the optics of the lens... it is all usable. Low beam cut off line (to avoid blinding on-coming cars) is in exactly the same place. So instead of an annoyingly bright light that blinds but doesn't necessarily penetrate further down the road and better on the sides ... this optimizes the optics of the lens to make the added light fully usable.
So in case you've been thinking ...
'76 R75/6
'94 K1100LT