Has anyone got any experience with regulatorrectifier.com?

[GGRider01]

Tried RM 125 CDI that is known to be good. The ignition coil on this bike is longer than on later bikes, and crossover seems to be limited to some husabergs and old KTMs (coil is Kokusan IG 3988, or ME25634006, KTM: 54739006000). See a pretty ratty one on eBay, I think I'll go OEM if I find that is the culprit.

The stator pickup is a P-01 and seems to be hard to source from anywhere in the US. Dealers could only offer me a complete OEM stator. The resistance on the pickup should be 100 ohms, so I'm going to get a meter and will find out quickly if that is the problem.

Anyone know what resistance values are supposed to be for the ignition coil? From the plug end to ground? If it is shot, it will be infinite, but if it is good I know there is some readable resistance and should be within a certain range - but that range is not knowledge that I possess.

[GGRider01]

Stator pickup 97 ohms
Ignition coil plug end to white/bluestripe wire 18.4 thousand ohms
AC voltage at the red and black wires that power the CDI when kicked over.
New stator from regulatorrectifier.com... (old one WAS BAD)
No bad connections, no unwanted connections to the frame.


No spark.


Exciter measured at the red/white and black/red wires was 24 ohms.. It's supposed to be 12.7. Would this prevent spark? Besides that, I've completely dissected the loom and verified every connection. No breaks, no grounds.. nothing! This is maddening.

Interesting to note, I got a peak voltage of 3.4 from the yellow lighting output while kicking like a mad man.. What is going on here?

[(F5)]

Line 2
way too high if yer measuring it right.
Take the cap off and measure just that. Should be 5k ohms, maybe 6. Coil ht wire to input should be a small number.

[Neil E.]

Just a quick note about using a meter. Disconnect any device you are testing. For example if you check those wires when they are also hooked up to the CDI, you will be measuring everything in the circuit and can get goofy readings.

Trust readings when you know the single device is the only thing present. If something reads more than 20% different than specification, it usually has a problem. High resistance (megohms) is approaching an open circuit. Low resistance (less than an ohm) is approaching a short circuit or actual good connection.

A winding that measures low ohms could mean that it is shorting from being wet (or shorting due to failed insulation). Failed parts or corroded parts often go "open" (this is high resistance, also called "infinity").

With your exciter at 24 ohms instead of 12.7 ohms, it might not be sendng enough power to the CDI. Can you get an AC voltage at your single winding output? I've never checked one, but I'd expect to get maybe 30 VAC on a strong kick. That winding has fine wire to create the maximum voltage rise.

AC output at your stator yellow wire will not be very high at kicking speeds, but 3.4 VAC seems a bit low. I think about 10 volts is reasonable.

Keep in mind that measuring AC voltage depends on how good your meter is. There is quite a difference between meters. Auto ranging meters have a lag to them and don't catch short pulses well. A fixed scale type meter might be better.

[lynngarner]

I have the same question on the 24 ohms vs the 12 ohms that the manual calls for: will the 24 ohm measurement at the exciter prevent spark at the plug?? If so, can the exciter be purchased separately, and is there a crossover part?
Thanks

[Neil E.]

From the 2006 GG workshop manual, all values +/- 20%:
Impulse Coil - red & green wires - 100 ohms (pickup sensor for ignition timing)
Exciter - black/red & red/white wires - 12.7 ohms (single winding powers CDI)
Charge Coil - yellow wire & earth - 0.67 ohms (lighting only)
Charge Coil - white & yellow wires - 0.16 ohms (charging, white & earth)

As mentioned before, I'm curious about the voltage produced by the exciter coil. I would expect that high resistance would produce less current in the winding causing lower voltage to the CDI. For creating sparks we know it's all about voltage.

It works like this (using approximate numbers):
1) the single winding creates 30 volts
2) the CDI steps this up to 300 volts
3) the ignition coil steps this up to 30,000 volts

To make a reliable spark takes a minimum of 15,000 volts so if the single winding output drops off, it's easy to lose the spark. I find it interesting that two guys have meaured 24 ohms at the exciter. Maybe it's time to try something else. Take a new plug and reduce the gap to 10 thou and see if you can get a spark. If so that may prove that there is just not enough output from the exciter winding to spark across a normal 25 thou gap. Use the recommended NGK BR8EG when testing.

The system on these bikes is a Kokusan 2K3, I expect most items would cross over with other brands of motorcycles.

[Neil E.]

Originally Posted by lynngarner

I have the same question on the 24 ohms vs the 12 ohms that the manual calls for: will the 24 ohm measurement at the exciter prevent spark at the plug?? If so, can the exciter be purchased separately, and is there a crossover part?
Thanks

Terminology might be messing us up, but the exciter is actually the special winding that is part of the stator. Replacement would be done by rewinding that post on the stator. Most of us would just buy a new stator.

[GGRider01]

Originally Posted by Neil E.

ake a new plug and reduce the gap to 10 thou and see if you can get a spark. If so that may prove that there is just not enough output from the exciter winding to spark across a normal 25 thou gap. Use the recommended NGK BR8EG when testing.

The system on these bikes is a Kokusan 2K3, I expect most items would cross over with other brands of motorcycles.

That is something I tried with no spark created. Tonight wasn't able to get outside to run any more tests on the ignition coil.

Oh BTW - My bike has the Kokusan 2k2. Looking to upgrade that later on.

As for the ignition coil ohms, it is in the ballpark for most automotive ignition coils, but probably too high for our use. Will test just the plug cap tomorrow - and input to the heavy wire (with cap removed)..



Ok - Plug cap reads 5.57 K Ohms. Ignition coil from input to heavy wire end (cap removed) is 12.84 K Ohms.. This doesn't sound unreasonable to me. However, looking up ignition coil tests for KTMs reveals something in the ballpark of 0.250 Ohms is desirable on this test. This will be the next part I replace. Looks like 2011 KTM 250XCF uses the same coil! Under part number 58439006000, Kokusan IG 3826. It's the same length, at least.

[GGRider01]

Final update: The bike is running. I bought a pretty scary looking stator and flywheel off of eBay for really cheap. I now have a 2k3 stator which I'm excited to convert to DC using the method stickied in this forum.

The new ignition coil gives me the exact same readings as the old one but I'm happy to not understand why it works until it breaks again.

[Neil E.]

What actual bike is it? Do you really need a DC system? How road legal are you trying to get the bike?