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xl250s 6v to 12v conversion

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Hi Thumpers,

Has anybody converted a 6v system to a 12 volt system on their bike? Any pointers welcome as i would like to do it on mine.

Thanks guys :thumbsup:

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i'm supposed to be testing one for a guy that has a motorsport electrics copmany out east... notice i said SUPPOSED to be. :thumbsup: I'da had it done to if he could have gotten it to me a week earlier this spring, but the busy season hit and its just starting to slow down. i keep hoping itll be soon. if they work out he's going to produce them and you can buy them from him. i'm testing it on a 350, but the 250's and 350s xl and tl all have the same set up. Unfortunately, this is for the older xls- '72 to '78. IF the 250s has the same system as the xl500s, you can buy the generator from a honda Ascot FT500. it was the same motor as the xl500 but was a 12 volt setup. good luck!

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I put a new 81 xl500 motor in my 82 xl500(which is 12v) and changed the flywheel,stator and the crank trigger but I had all the electronics from the 82 like the regulator.I think you would have a hard time fitting a 12v battery in there but a little ingeniuty and a couple of manuals for each bike it could be done.Dont forget you will need to change all light bulbs and flasher to 12v.:cheers:

I just realized this was a 250 you were asking about not a 500 sorry I cant remember if the 82 xl250 was 12v but if it is you could use those parts

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a conversion for the older 250s and 350s has been done... i have it sitting on my workbench waiting for me to find the time to put it in. It's not bumping up the wattage much, if any, just converting it to a 12v system. Actually pretty easy on the XL's, because there are 3 coils in the stator. one that runs the headlight, one that charges the battery, and one that runs the ignition. The guy that rewound it for me tied the batter and headlight coils together with bigger wire and different # of winds. gotta get that in sometime soon... to many stinkin projects.

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I had a 78 XL250S and I hated that headlight. It was about as bright as a candle, and had the same orange color. I wanted to be able to ride at night. The stock lighting didn't cut it. I started a quest to run a 12 volt halogen headlight. The most straightforward way is to rewind the lighting coil. Just put twice as many turns of smaller wire on there and it should work fine.

Before opening up the engine like that I thought why not try a voltage doubler. So I wired one up and tried it with a 35 watt bulb. I started the bike and it worked great! However, my setup had no regulator. A soon as I reved the engine the bulb burned out. I tried again with a 55 watt bulb and it was perfect. Just the right wattage for the coil. I had about 13 volts on the bulb. Ran this system until the bike died. I also ran this on an 81 XR500R and a 82 XR250R. With no regulator getting the right wattage is important. Too low and the bulb burns out. Too high and the bulb never gets to proper output. The 55 watt bulb worked best for these 3 bikes.

One issue that has to be considered is that the output of the voltage doubler is -6 volts and +6 volts with respect to the frame. Because of this the shell of the headlight has to be insulated from the frame of the bike. Depending on the headlight mount this can be an easy problem or an impossible one. I used a car driving light for my headlight and used a cut up 2 liter soda bottle to insluate the reflector shell from the rest of the headlight.

I believe that I have one of these setups somewhere in a box in my garage. I think that I have the parts to make another. They are not pretty, but they work. It consists of a bridge rectifer and two big capacitors wired up as a voltage doubler.

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I had a 78 XL250S and I hated that headlight. It was about as bright as a candle, and had the same orange color. I wanted to be able to ride at night. The stock lighting didn't cut it. I started a quest to run a 12 volt halogen headlight. The most straightforward way is to rewind the lighting coil. Just put twice as many turns of smaller wire on there and it should work fine.

Before opening up the engine like that I thought why not try a voltage doubler. So I wired one up and tried it with a 35 watt bulb. I started the bike and it worked great! However, my setup had no regulator. A soon as I reved the engine the bulb burned out. I tried again with a 55 watt bulb and it was perfect. Just the right wattage for the coil. I had about 13 volts on the bulb. Ran this system until the bike died. I also ran this on an 81 XR500R and a 82 XR250R. With no regulator getting the right wattage is important. Too low and the bulb burns out. Too high and the bulb never gets to proper output. The 55 watt bulb worked best for these 3 bikes.

One issue that has to be considered is that the output of the voltage doubler is -6 volts and +6 volts with respect to the frame. Because of this the shell of the headlight has to be insulated from the frame of the bike. Depending on the headlight mount this can be an easy problem or an impossible one. I used a car driving light for my headlight and used a cut up 2 liter soda bottle to insluate the reflector shell from the rest of the headlight.

I believe that I have one of these setups somewhere in a box in my garage. I think that I have the parts to make another. They are not pretty, but they work. It consists of a bridge rectifer and two big capacitors wired up as a voltage doubler.

Hmmm, I'm gonna send you a PM...

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i'm supposed to be testing one for a guy that has a motorsport electrics copmany out east... notice i said SUPPOSED to be. :bonk: I'da had it done to if he could have gotten it to me a week earlier this spring, but the busy season hit and its just starting to slow down. i keep hoping itll be soon. if they work out he's going to produce them and you can buy them from him. i'm testing it on a 350, but the 250's and 350s xl and tl all have the same set up. Unfortunately, this is for the older xls- '72 to '78. IF the 250s has the same system as the xl500s, you can buy the generator from a honda Ascot FT500. it was the same motor as the xl500 but was a 12 volt setup. good luck!

any luck with this i know it was 7 years ago...

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