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Dual Sport electrical wiring/ Honda XR

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I'm trying to figure out the dual sport wiring again, on my custom Honda bike.. '86 XR250R is what the engine block started out as, but its all custom engine and bike from there, bored/stroked XR305cc. I wired it up street legal before, and had things wrong... the battery pack melted and was destroyed.


I have some pictures to show and explain, and some (3) basic questions.

here is the bike street legal before:


coming back together now rebuilt!:


stock XR250R wiring diagram from haynes manual:


which is basically the same diagram as this:


(A/C powers the head and tail light in stock config, no DC system at all)

Red circled wires are what I have open from my regulator here, I'm just not sure if its a stock-like AC regulator or actually a DC rectifier...?:



Numbers on the side 620403, I couldn't find through quick google search..

That's Question #1, is this device a DC Rectifier or a AC regulator only?


I just purchased this (red circled) motorcycle AC regulator:


It is just a one wire regulator, Black is ground and the yellow wire is AC positive right?

That is my Question #2, how is this wired how can it regulate AC if not inline with an AC hot wire? Do I need this in my setup?


On to the last step, I have a Tusk Enduro universal wiring harness that runs all the DC system & battery & ties all the components together:


That aftermarket harness could run all DC components separate straight off the battery excluding head/tail still run off AC power, but that way would require plugging the bike into house power every night to float charge the battery.

I obviously want my bike wired like a regular enduro, so when the engine is running it is charging the battery with just over 12V DC. So, say I figure out my regulator/rectifier situation to give me DC output.. Question #3:

So I wire the rectifier DC +/- output straight to the Tusk harness at the battery +/- connections?


Then, what about the Tusk harness yellow/black on/off switch wires at the top of picture? This is on/off for DC components attached to that harness I believe... But I have a 4-wire ignition switch with key, how do I wire this between the bike's stock harness and the aftermarket Tusk harness, so that turning the key off will kill the engine AND cut all DC power/lights at the same time? Wire in key up inline with stock harness' engine kill switch?


I'm almost there but I can't for the life of me find straight info or explanations from friends..




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aaaahhhhh why can't I find anything about 620403? It looks like an old Trail Tech regulator/rectifier, except it has 4 wires not 5..

How do I wire the new motorcycle AC regulator inbetween the stator output and the rectifier/regulator, and what's the best reg./rctfy. unit I can purchase online if mine isn't giving DC output? Or another common bike I can steal a rectifier/regulator from in the bike boneyard?



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I am having the same problem with my Xr400. I gave up and bought a drz lol but I would also like to find out how to get the xr all wired up right.  From the little i know the stator makes AC the regulator-rectifier-unit connects to the stator ( yellow wires connect to pink and yellow of the stock harness) The regulator-rectifier-unit converts the AC to DC so that the battery can be charged as you ride.  The Red and Black leads connect to the battery. Hope this helps you a little.

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I know....

just hoping that aftermarket-looking box I have is in fact a DC rectifier.

I'm trying to get carb/exhaust on my engine now so I can start it and try to test with a voltmeter

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it is a single phase rec/reg made by Tymapanium. Made in the 2 week of 1994.


excellent! thanks. so, is an AC regulator like this not needed at all for me:


still not sure how you'd even wire that, black AC frame ground and yellow to the stator primary wire?


I couldn't start my bike yet to test voltage, because I got a wrong version of the same Mikuni TM36-2 carb I had previous, and the new one doesn't fit, waiting for another one now then I'll get all my intake/exhaust together.


So, I should float the DC ground from the Tymapanium unit, black and red 12v DC -/+?

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Did you ever get this sorted out? I just wired up my XR600r, took a fantastic 30 mile ride, and then right at the end my battery melted out the side of my frame. 

Everything else worked great during that period, but I guess the voltage was too high for my battery? If I lower the charging voltage on the TrailTech regulator/rectifier my LED lights start to flicker. Looking for answers...


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