XL500s project - 12v conversion questions

[Parkwood60]

Wait, is it already a CDI, just running on 6v? Now I'm not certain about making that work, but you can add a resistor to bring the voltage down from 12 to 6 just to run the original CDI system. Maybe that is what he was talking about?

And now I realize the XL500s wiring diagram I posted was in fact the right one for your bike. But here is a guy saying he did it with just a swap of the reg/rec unit http://www.advrider.com/forums/showpost.php?p=10399283&postcount=8

 

[epidemiks]

Yep already cdi. I'd also read that just swapping the reg/rec would do it but came across a post somewhere (can't find it now) saying that if the timing isn't sorted that it'll eventually burn oun the valves

 

[epidemiks]

Here's the electrical diagram from the Haynes manual. Does indeed look like it comes straight from the stator to the headlight.

The main reason I went this path is because I figured it would offer better lighting via LEDs, but if I don't need to, I'm not so far along that I can't rewind and just fit a suitable new cdi and reg/rec and be done.

Planning to drop the rear a bit too to make up for the loss of trail and have the forks 65mm through the triples to test the impact of a smaller wheel. Intend to have an end product that is functional, not just style.

 

[Parkwood60]

I am not an electrical engineer, but you should be able to use the stock CDI box with the mechanical advancer as long as you fit the proper resistor in the circuit so it still only sees 6 volts, or maybe 8 volts. Doesn't matter really as long as it only sees as much voltage as it can handle without melting down.


But again, I just had a look at the diagram. I'm not a fan of telling newbies to RTFM, but you really need to read an understand that diagram before you start messing with it. The power for the CDI box comes from a completely separate charging coil than than the headlight, and the rest of the bike. One winding powers the headlight. One winding powers the CDI box/coil/spark. One winding powers the rest of the electrical system. Only the winding that powers the battery, brakes lights, taillights, turn signals has a regulator/rectifier in it. So, changing the rest of the bike to 12v won't affect your CDI box at all.

 

[epidemiks]

I'm not adverse to being told how it is, so thanks for your comments parkwood60. I'm reading it, just not yet fully understanding it!

Really, this is good news anyway. Not least because I'm in over my head.. So what you're saying is I could scrap the 12v stator upgrade, leave the cdi as is, swap out the old rec/reg for a new 12v one and pop in some 12v lights and go? (which I believe was already suggested earlier...)

 

[swoops]

Very curious how this worked out! Did you try LEDs on the original stator?

I have an '81 XL250 with a headlight problem, and I am looking at all options.

 

[gaz88]

Hi folks. Any update on how the 12V conversion went? Many thanks, Gary