KDX Lighting Stator Rewind How-To

[chkdx]

Man, I wish I knew, Nick. I really don't know why a better lighting coil helps the ignition, but enough people have noted it that I think it has to be real.

I can tell you that generally, as long as the mixture is reliably ignited, a stronger spark doesn't usually cause a power increase in gasoline engines. I spent 13 years at Mallory ignition, and we tested this to death. A stronger spark will more reliably ignite lean mixtures, but at "best power" mixtures, a stronger spark really doesn't help.

We DID find, however, that some engines are pretty sensitive to spark timing, and I do wonder if the stronger lighting coil is somehow changing the spark timing vs rpm to something the KDX engine likes better. That's just a theory on my part, though. I hope someday to have the time to really test this theory.

[Julien D]

Great work Nick :)

It's great that you went to the trouble to really test this correctly, and provide that info out here for everyone.

[Slick_Nick]

Great work Nick :)

It's great that you went to the trouble to really test this correctly, and provide that info out here for everyone.

I learned alot in the process!

Still not impressed with the results of a DIY rewind?

[rbates9]

I think that the point the OP was making was that you can make your own for cheap that puts out more power than stock. I think he did a great job showing everyone what to do and how to do it. Getting down to splitting watts don't really matter. If you want one that has a certified rating go buy one.

I think the idea here is to establish what the actual gains Nick has
accomplished with his rewind as it seems to have a pretty wide
range of interest on the site.
Getting down to splitting watts really DOES really matter and that's why
there are the specific questions and Nick is doing a pretty good job
of testing his work and providing documented evidence to support his
claims.

Kudo's to Nick going through and answering all the questions and
if it really don't matter to you Bates why you wasting your time reading this thread ?

MOODY, It just seemed that there was a lot of doubt and nit picking over his claims right from the start. Yes Nick did a great job not only doing the rewind but also in explaining and testing. He was looking for a brighter headlight and it seems as tho he got what he was after.

The reason I was reading this post is because I am interested in the how to part and if it worked out or not. Not if it put out 98 watts or 97 watts.

He had readings of 83-103 watts and then YOU nocked it down to 70-75?

Also if you are looking for an EXACT watt out put there should be EXACT RPMs along with the readings. What is his bike idling at? what is your bike idling at? He listed the gauge of the wire but not the thickness of the insulation, that could change how many wraps of wire are on the stator. Also how tight it was wrapped could also change how many inches of wire are on there, which would also change the output of the stator. Resistance in the wiring and temperature also plays a part in electrical readings


Great job Nick, excellent job with the how to and readings. I had no doubt of the stator from the start and I'm glad you took the time to prove your results. I am not trying to discredit you or your post. Just answer MOODY's question.

[TWMOODY]

BATES,
Nick ask you to be his BIG SISTER and protect him from internet bullies
or something ??

I'm sure the spec on the OE coil was not tested at 11.3 volts
so to say anything else is wrong !

Moral of the story here Bates is that
You can believe what ever fairy tale you like.

[Slick_Nick]

Easy guys...

Thanks Bates for the kind words, the wire is not insulated, just coated, so I would venture a guess that the coating doesn't account for much in the way of increased thickness. I don't know the exact RPM of each test, no. Every digital tach I can find is for four strokes, so it reads double on a two stroke...

[rbates9]

MOODY, what was the stock coil tested at? I have been up for nights thinking about that.
It troubles me to no end that I am not 100% sure what my lighting system is capable of. There is a coffee maker I have had an eye on for those early morning rides that I would love to get but I will still need the head light to work as well. If I get you the information on it could you tell me if it will work? Thanks.

[rbates9]

Easy guys...

Thanks Bates for the kind words, the wire is not insulated, just coated, so I would venture a guess that the coating doesn't account for much in the way of increased thickness. I don't know the exact RPM of each test, no. Every digital tach I can find is for four strokes, so it reads double on a two stroke...

As far as I'm concerned it doesn't really matter that much if at all, just making a point. Every bike is a little bit different. You could send the parts to me and I would get different readings. Not by much, but I'm sure they would be different. Again great work.

[chkdx]

One last question Nick. You used 17 gage wire. Where did you find it? I can find 16 gage and 18 gage, but not 17 gage, in fact this is the first case I've heard of 17 gage wire being available. Maybe it's a metric size that equates to 17 gage?

[TWMOODY]

MOODY, what was the stock coil tested at? I have been up for nights thinking about that.
It troubles me to no end that I am not 100% sure what my lighting system is capable of. There is a coffee maker I have had an eye on for those early morning rides that I would love to get but I will still need the head light to work as well. If I get you the information on it could you tell me if it will work? Thanks.

Bates,
I'm glad some people learned some basic electrical skills here
on how to properly test an electrical system.
Obviously you have not !

There have been 539 views on this thread so far and has really
created a good amount of interest.
Of those 539 views YOU have been the only one to post negative
comments.
You might think about that before you post you next round of stupidity.

[Slick_Nick]

Might have been mistaken, it could have been 16 or 18, sorry for the confusion! 18 sounds right to me...

[chkdx]

Cool, Nick, no prob, it does look like 18 gage in the photos. I am definitely going to to shamelessly copy your idea for my KDX! Thanks again for showing us how to do it right!

[rbates9]

MOODY, what was the stock coil tested at? I have been up for nights thinking about that.
It troubles me to no end that I am not 100% sure what my lighting system is capable of. There is a coffee maker I have had an eye on for those early morning rides that I would love to get but I will still need the head light to work as well. If I get you the information on it could you tell me if it will work? Thanks.

Bates,
I'm glad some people learned some basic electrical skills here
on how to properly test an electrical system.
Obviously you have not !

There have been 539 views on this thread so far and has really
created a good amount of interest.
Of those 539 views YOU have been the only one to post negative
comments.
You might think about that before you post you next round of stupidity.

PLEASE REREAD THE POST.

I don't belive I have posted any negative responses to this thread. Read my first post.

As far as the personal attacks, this is not the forum for that. There are other places to do so. And for what it's worth you are the one that started with the stupidity.

If you could please list out the other mods to your bike and the exact improvement. Not just what you think it did.

[Slick_Nick]

I would LOVE to get an SR stator plate and rewind both lighting stators! Can you say 180W of juice?

[Varmint]

Well, I actually am an electrical engineer, so I thought I'd throw a thought in here. Nick, your first test was in fact incorrect. You measured open circuit voltage and short circuit current separately, so they cannot be multiplied together to obtain the correct wattage. You do, indeed, have to measure them simultaneously to get the real wattage.

Think of it like a fuel pump. If you measure the pump's output pressure with the outlet blocked by the pressure gage, the reading will be the max pressure the pump can put out. If you then check the flow by just running the pump output into a bucket, the pump is putting up plenty of flow, but no pressure, so it's incorrect to say "This pump puts out 30 gallons per hour at 15 PSI" when the pump's max pressure was 15 PSI.

Now you brought up the regulator. Let's add a pressure regulator to the fuel pump, and set it at 12.5 PSI (kinda like the 12.5 volts of a voltage regulator). If you then run the output of the regulator into a bucket, the output pressure is still zero, not 12.5 PSI, so it's still not a valid test. What you have to do is restrict the outlet flow (with, say a valve) until the pressure before the valve just barely drops just below 12.5 PSI, say to 12 PSI then measure the flow out of the valve. You can then say "This pump flows X gallons per hour at 12 PSI."

Similarly, the right way to do your electrical test is to restrict the current flow through the ammeter, with resistors or extra bulbs, until the voltage seen by those resistors or bulbs is, say, 12 Volts, then note the amperage. You can then say "The output is X amps at 12 volts, therefore the wattage is X amps times 12 volts." Note: the resistors or bulbs are put in series with the ammeter for this test.

You are correct that trying to measure output at much above 12 volts won't work as the regulator will shunt current to ground to maintain around 12.5 volts. However, you may well find (probably WILL find) that if you rev the engine up to say 5000 rpm during the test, you'll have to reduce the test resistance to keep the voltage at 12 Volts, so more current will flow, and available wattage will therefore be increased at higher rpm.

Clear as mud? Hope it helps! I'll be watching this closely as I'm going to try rewinding my stator as well.

This was a very interesting thread. Nice job Nick. We got some smart folks on here. Inda would have loved this thread.

I got my first "D" in EE in college; passed by the skin of my teeth. The above quotation brought back nightmares. Then I thought of this...

[youtube][/youtube]

[chkdx]

HA! I wonder how many takes had to be done before that guy got thru it without laughing!

[SS109]

I would LOVE to get an SR stator plate and rewind both lighting stators! Can you say 180W of juice?

Yeah, me too! I tried to locate an SR stator for a while but gave up. Oh well!

[SS109]

One last question Nick. You used 17 gage wire. Where did you find it? I can find 16 gage and 18 gage, but not 17 gage, in fact this is the first case I've heard of 17 gage wire being available. Maybe it's a metric size that equates to 17 gage?

I just had to add this in here: http://www.alltronics.com/cgi-bin/item/ ... agnet-Wire IIRC, it was Vince himself that originally said to use 17ga wire.

Also, Nick, you never said what weight of spool you bought. Was it 1/4, 1/2, or ??? I need to know as I don't want to buy too small a spool! Also, where did you buy your wire?

[Slick_Nick]

A store in town here carries this stuff, I wish I could remember how much but it was a spool, about 2" around, it did the stator and had about 10ft extra.

Here's the link of what I got, doesn't say how big the spool is though: http://www.active123.com/eng/storeSecti ... vel2=43503

[Slick_Nick]

A 1/2Lb spool would be about right IIRC.