Honda Motorcycle XR650R Stator Addendum How To Rewind Stators

I also rewound my stator using that website as a guide, but did it slightly different. Instead of splicing into the stock windings, I kept them as two different circuits. The stock wiring powers a set of heated grips, the new windings powering the headlight. I think the stock windings on the US model (4 poles) puts out about 74 watts. The new windings (6 poles) have more wire on them than the stock ones, so I’m guessing that there’s at least 125 watts coming out of there.
I used the stock voltage regulator on the new circuit with the headlight and left the other circuit to the grips unregulated. I’m not sure if this is a proper setup, maybe someone with a better electrical knowledge could help me out.

As for the light itself, Wal Mart sells rectangular driving lamps (the kind that would mount to a truck bumper) that is almost the exact same size as the stock unit.

You’ll have to be a little creative mounting them in the number plate.They sell for $16 for two and come powered with H3 55w bulbs. For an extra $2 (in the same isle) you can get a 100 watt H3 bulb for more brightness. I went all out and got a Diamond white bulb from the JC Whitney catalog and this setup works very well. It’s bright, looks stock and is cheap. Now if you could fit a H4 bulb in there somehow…

I’ve done both setups; a 55/60 on a high output stator with BD wiring, and a 90/100 on a super high output stator with custom wiring. Both had the same BD headlight mask and headlight lens.

From a simplicity point of view, going with a 55/60 setup wins hands down. You have approximately half of the electric current to deal with, which means the smaller wires from the stator and in the BD harness can be used as is. Same goes for the headlight switch. Buy a quality bulb such as the Sylvania Cool Blue (which isn’t really blue at all, but rather white) and the difference between that and a std. 90/100 in the same lens isn’t that overwhelming.

Winding the lower power stator is easier as well – you simply strip off all the original wire (comes of real easy) and wind on three wraps deep per pole, over all 10 poles of #18 wire.
There are usually 11 turns per wrap, giving about 330 turns total.
Should take less than 50′ of wire. Final output is slightly above the 100W mark. This works well with the BD kit, (60W headlight, 10W of taillights, 5W DRL; leaves 25W for charging/brake/turn.)

** NOTE: **
You may see that others have wrapped the previously empty 6 poles with 5 wraps of #18 wire and then connected that to the end of the stock 4 poles. This takes essentially the same length of #18 wire as the above, but has less output (approx 70W) and is less efficient (generates more heat in the engine).

The high power stator (well in excess of 100W) requires you to make two groups of 330 turns #18 connected in parallel, or to wind 300+ turns with the heavier #16. Then you should replace the wires from the stator core to up under the seat with heavier ones as well. Next, you start wondering about the size of the rest of the wires, and the load capacity of the headlight switch…

I meant to tidy up some of the documentation on the little stator simulation program I wrote before unleashing it here, but didn’t get around to it yet (hey, given the choice, you’d have gone riding instead too!) I’ll try to do that b4 the end of the week…

I’m thinking about rewinding my stator so I can go to a 55/60w or 90/100w setup and also have my battery remain charged.
I’ve read most of the posts regarding the rewind and was wondering if any of you who have tried it are happy with the results and what you learned in the process.
Is the dual output method the way to go with the BD kit?

I decided that winding three more coils would be sufficient to run a 100 watt halogen. I based this on the fact that our stock 4 coil system is rated at 80 watts (20 watts per coil) Baja Designs strips the original 4 and rewinds all 10. They wind them larger and then grind the case cover out for clearance. This gives them 250 watts total (25 watts per coil), but they make their system a dual output system (2 x 125). So, winding three more and running all 7 in series should make the stator capable of 140 watts output.

The stock system…. I didn’t do any baseline readings on my bike before the rewind, but my brother has the same bike and I did baseline his. At idle, the 35 watt incandesant was drawing about 2.6 amps at around 12.3 volts. Apply Ohms law of P (power or watts) = V (voltage) x I (current) and you get about 32 watts. However, when reved up, the current draw dropped to around 2.1 and the voltage to 11.6! This would mean the light would dim while riding! This sucks! When we installed the Baja Designs Light Improvement Kit (Older XR light housing with a glass lense and 55 watt halogen), the current was right at about 3.6A. The current didn’t drop off when reved with the 55 watt bulb, insted it increased to about 3.9A with the output voltage right around 14. This equates to 54.6 watts.

I need to point out a problem with Honda’s wiring of the stator coils. On Eric’s bike, as well as my brothers, the first coil is wound clockwise and is tied to the “green” wire and the last coil wound counter clockwise is tied to the yellow/white wire. My bike had the the yellow/white to the first coil and the green to the last!
Honda wouldn’t do something like this would they? This may seem like an insignificant detail until you tie your new coils to the old and get clockwise to clockwise, or counter clockwise to counter clockwise coils in series. This would subtract the induced voltages instead of adding. Verify yours before before breaking and making the new connections.

To make a long story short, both bikes have been rewired and draw close to 7 A@ 14.xx volts (bike reved) for the expected 100 watts.
I just remembered. The stock stator output was 60 vac maximum. The rewound stator with all 7 coils in series produced close to 130 vac.
Light is damn bright, but haven’t got to do a mega night ride yet.

Anyway, some time ago, I got a high wattage electrical system all dialed in with a 16 gauge single wind on all ten poles, a 100/90W bulb, and a new 16 gauge headlight harness. I have been using it for a while now without any electrical trouble. However, I have a problem I can’t seem to get around easily and that is the headlight lens for the BD DSK doesn’t withstand the extreme heat the 100 Watt bulb generates. The surface of the reflector (behind the glass) melts causing it to cloud and greatly reduce the headlights’s efficiency. The only solution is to use a different lens configuration, either one that can withstand the extreme heat of a 100 Watt bulb or a dual 60/55W setup. Neither of those is going to work out for me at this time. Since I have another stock stator, I’ve decided to go back to an 8 pole 18 gauge wind running a 60/55W lamp in *another* new BD DSK headlight lens. I’ll hang on to the 16 gauge stator in case I decide to go to a different lens configuration down the road.

The problem I’ve run into now is that Mouser Electronics no longer stocks the 2216 epoxy and will only order a minimum of 6 tubes with a 3 week lead time.
Do you know anywhere else to get that stuff?

Sure looks like the HP lens (at least from the back). It has the slight curvature to the sides and the mounting looks the same. A guy named Clint was asking me about bulbs, and he had a split/dual wind with 320 turns on 5 poles (times two) and he figured he needed about 1500 RPM to get full bright on a 55W bulb. In contrast, the 320 turns over all 10 poles pulls a 55W and a tail+brake light (25W or so) to full bright at even a low idle. I’ve never been a fan of the fragmented power you get from a split winding. In Dirt Rider’s 24h they take a system with split windings runnning 1/2 AC, 1/2 DC and convert it to a single winding with all DC so that the power isn’t fragmented. I think it was a WR. Not sure.

This is fine if you only intend to drive a 55W bulb, but if you want more zap (e.g. for 100W) you will need to do a parallel configuration.

The wiring of the additional stator posts in series drives my tail light/brake light (16W), license plate bulb (5W), horn and 100W halogen headlight bulb just fine.

All of the lights are on constantly. The 100W bulb is extremely bright from a great distance (verified by my wife) and the intensity at idle is excellent.

This is a topic of interest for me, so bear with me as I ramble on 🙂
I am curious if you tried to actually measure the voltage when under load and without the regulator involved. The reason I ask is that the 100W bulbs can appear quite bright, even when operated at a lower voltage (such as 10 volts).

The reason I say “without the regulator involved” is that the regulator results in a truncated sine wave output, and for the readings of a typical RMS AC volt multimeter to have any meaning, the input should be an unmolested sine wave.

I have an example to back up why I think parallel is the way to go.
An XR600 stator (which has same # of poles as 650, in fact it may be an identical stator…) that has been stripped of the 4 poles of #20 and rewound with #18 copper (all poles in series) is able to pull 8.6 VAC with a 100W H3 bulb directly across the stator at idle. The voltage plateaus at 9.9 VAC for all RPMs above approx 1800RPM. This is a true indicator of max power output since no regulator is involved and all power is directed through the bulb. This was with a cold engine. As the engine gets hotter, resistance of the copper wire in the stator goes up and so you will have slightly less power again.

Now, should one run a 100W H3 or a 55W H3 on this bike? With the 100W bulb fitted, it seems pretty bright, so that doesn’t help. So I set up two identical factory Honda lights (i.e. the “BD lighting improvement kit”) with one of each bulbs. There is no question that the 100W is brighter when both are operating at 13V. When I dropped the voltage on the 100W bulb below about 10 or 11 volts, the balance starts to swing the other way, and the 55W bulb at 13V becomes the brighter one. (This is why people run relays on high power car/off road lights – the voltage drop along small wire that goes to the switch and back is intolerable.)

Back to the XR600 example – it has plenty of jam for a 55W bulb (which was all that was desired by the owner), but it is not enough to run a 100W bulb at peak efficiency. Splitting it into two groups of 5 poles might have been a better choice, so long as the idle voltage was still satisfactory – I think it would be. If not, two groups of 5 with #20 wire would give more turns and thus a higher idle voltage (tradeoff being a reistance increase of course). I don’t know whether BD uses #18 or #20 in their 2×125 stator, but the fact that it is listed as “2 x …” tells you it is two groups of 5 poles that can be connected in parallel and not just 10 poles in series.

Assuming you have determined that a parallel config will have enough voltage at idle (not as much an issue if you have a battery), then a parallel setup wins over an identical series setup for two main reasons. The first is that the overall parallel resistance will be 1/4 of a series configuration with the same wire size and number of turns. Second is that the current through any given pole will be half (for the same overall current load), and so the magnetic field generated by the pole that opposes your flywheel magnet (and thus limits your max output) will be only half as strong as the series case.
I’ve personal experience with another stator example for an XR250 where the difference in output of a parallel setup over a series setup was quite surprising, but I won’t bore the list with the details as I’ve rambled too much already. Hopefully some on the list have found it educational/amusing…

Anyway, I haven’t any test data on the setup recommended on the internet (i.e. with the stock 4 poles of #20 and 6 poles added in series of #18) which is why I am genuinely interested. You do get more turns per pole with #20, but that also translates into more wire length, and #20 has about 60% more resistance/ft than #18 as well. So I do know that it will have a higher resistance than the XR600 example given above (all #18), and that is why I was wondering if you actually measured the output to be a true 100W or more.

I too was originally concerned with higher currents and whether there would be unacceptable voltage loss over the stock wiring. But my experince has indicated that the stock wiring will do an adequate job in most cases.

It is important to note that: [A] The wires from stator to regulator will operate at the full current capacity of the stator ALL the time, due to the “clamping” or shunting nature of the regulator. [B] The wires from the regulator on out to the lights will only be flowing current equal to the load of the lights (and any other accesories people glue on).

On a 400 with the stator winding I described (3 layers deep of #18 on 10 poles) we left the main wiring harness stock. Total output is low enough that [A] is not a problem. Originally this bike was intended to run a 55/60W headlight, but testing with a 90/100W revealed that this stator config had the power to do it, so we went with that bulb.
The only time the headlight is observed to dim slightly is if high beam is selected AND the bike is idling AND the 20W brake light is applied.
This rewind gives a good bright setup, and no wiring upgrades involved.

On a 600 with a higher output stator (150+) we did upgrade the wires from the stator to the regulator in light of [A]. The rest of the wiring was left stock, and it too ran a 100W headlight, plus intermittent brake, turn and horn loads.

So, if a person wanted to be super ambitious and minimize losses to the extreme, then you could run heavier wire from the stator to the big load (headlight), and relocate the regulator as close to the big load as possible. This becomes more important if you run a massive stator and ever bigger electrical loads. But for Joe Average, the biggest gains with the least amount of grief are to be had by rewinding an intermediate stator (3 layers #18 on 10) and leaving the stock wiring (and regulator) as is.

The three layers deep of #18 over all 10 poles is what I’d recommend to anyone that is in there doing a 400/600/650 stator and wants enough for a 60W headlight + 20W brake light and a bit left over for other things. The overall resistance is much lower than the #18 + #20 setup and so it is considerably more efficient.