How to get 12v from a 6v power source?

I have a 1982 Honda C70 Passport, it has a 12v battery. I changed all the blinker lights and the brake light to 12v led lights. The head light on the other hand is a 6v 25w light and runs directly from the power created by the engines stator. I was wondering if it's possible to boost the 6v to 12v? I also have looked for 6v 25w led headlight bulbs, but it seems 6v are in the past and I can't seem to find any for sale. The only option I see is upgrading the engine or hooking the headlight to the battery power, but I fear this will kill my battery faster and this isn't how the manufacture intended it. Any ideas as to get the 12v led working from a 6v power source?

This makes No Sense. If it has a 12 volt battery, it IS a 12 volt "source".

A 6 volt headlamp on a 12 volt system will burn out Very Quickly.

Look Closer. I'll bet it's 12 volts. You can put in a 12 volt halogen Phillips-Osram brighter unit. Available at Wal Mart. Or, an LED.

EDIT: ? Don't ask for help then Argue. Nor shoot t the Messenger. I WAS going to tell you about swtchmode inverters, 6v to 12v, but your post is so Nebulous.

I do not know what is this obsession with LEDs. The bike is not broken, do not fix it. Put a replacement regular or halogen headlight assembly available at all bike stores and online. It worked before and should still work now. And the stator voltage going to the headlight is AC, not 6V DC. The AC voltage increases with the RPM that is why the headlight is brighter when you rev the bike.

https://www.ebay.com/...-headlight

I'm not a sparky by any means but fitting a 12v battery to a 6v system battery does not give you a 12v system. The charge coming off the alternator will be 6v and I'd say the battery will not receive enough current to charge. The lights may work when the motor is running as the alternator may deliver enough grunt to light them up, but with no ignition they probably won't flash. Note that if the headlamp draws power direct from the alternator, it means that the battery is only there to power indicators and other minor electrics (horn) when the motor is either not running or not spinning fast enough to generate enough current (i.e at idle). LEDs can accept a wider range of voltage than regular bulbs, so you may find a "12v" LED may light up with as little as 7-8v (look on the back) and you may be able to get away with running a 12v bulb. Othersie, as someone suggested, get an upgraded 6v tungsten or halogen bulb instead, or wire up a pair of 12v driving lamps to the battery. The lights on these small bikes are more to be seen than to see by, so don't expect them to be able to melt stuff at 100yds

Mopeds and little mc's can have a "lighting coil" portion of the rotor / stator that puts out 1/2 wave, not full-wave rectified, current, as you indicate, just for the headlight. Like dude, there are thingies called voltage doublers and switching power supplies, but to make 'em work is going to require electrical engineering above your skill level. I suggest finding a led for a bicycle or even a flashlight… Something that works on 6 volts. The big 4 cell flashlights have 'em. 4 x 1.5 volts = 6 volts. The 6 volt spotlights have 'em. Those big square batteries are 6 volts, dude.