The 6 V A/C lighting of the XR500 and XR500R is notoriously weak.
At the front we find a D/C bulb with dual filament and a Zener diode in its base to rectify the 6 V A/C current. Only one of the filaments is used.
At the rear, a tiny bulb for symbolic presence.
Many of us would love to use the later XR500R 12 V glass lens at the front for safer night riding.
What is the simplest way to get 12 V out of the 6 V set up? Searching the Web you can find all sorts of tricks, most of them have not been tried by their authors.
After researching all sorts of other possible set-ups with aftermarket regulators-rectifiers and capacitors, I settled on a very simple solution.
Material needed:
- one triple coil setup from a XL500S
- one 12 V regulator from a XL500R
Procedure:
1- Remove trom the triple coil set up the small copper coil and toss it in the bin, you don't need it.
You are now left with 2 coils, one with a black wire that feeds the CDI with up to 50 V, and one with a white wire that will give up to 20 V A/C
2- Connect the white wire to the white/yellow wire of the XL500R regulator + the wire(s) feeding the front AND the rear lights: yes one wire will feed 3 items, fronte, rear and regulator
3- Connect the green wire from the regulator to the ground
(4- Of course connect the black wire from the stator ignition coil to the black wire of the CDI and sort out the CDI + ignition coil + spark plug set up).