I tested the various leads that the Clymer shop manual refers to and checked the resistance of all the leads. All the leads have close to the recommended resistance. I do not know how low is acceptable. The one set of leads that shown as open was the brown and black leads when tested. It was supposed to be 790 ohms I think, but the multimeter just read "OL".

I also called the bike shop that did the work on my jug, he says that just because it is old (1973 MX 250) that the small winding he called the "pulsor" the one that tells the spark plug to do its thing, was most likely at fault. He said the wire is so fine of gauge that it degrades over time.

Rather than buying a whole stator, does anybody know if the black and brown wire issue I have points to the pulsor, or something else?

The 73-74 MX service manual in the Tech Library has detailed CDI info. 

Brown is one of the charge coil colors... pretty sure the early CDI models had a "high speed" and "low speed" charge coil. 

Yep partzilla says 790 & 84 for the red to black. doesn't give pulser readings but guess 100 between whte red & white green. I'll go look it up later but anything is better than nothing & you have nothing on the main charge coil brown so gotta sort that. 

Yes I was getting 75 or something like that on the red/black. The brown/black is the main charge coil, that sounds like it will be an expensive fix. Any part of the CDI is expensive, but if the pulser is prone to failure, and the main charge is bad, it sounds like I do need the whole stator. I can only pray that the CDI box is still good.

I wasn't getting a reading at the ignition coil either. Looking at the plug cap there was some corrosion, so I optimistically thought that was the problem. I have a spare cap that I can swap out as soon as I figure out how to replace it. Should be easy, it has been decades since I messed with this stuff.

By the way, my tank is toast, I used the straps, it came in some , that when I seen the rear mount going in a direction it didn't need to go. It bent up at a 45 degree angle.

are uk or usa? Im UK, I have a full set of everything for a 75 dt400b if its the same, full stator plate, cdi, rectifier  coil etc all work

Just get a DT250A points mag & the cover then ride off into the sunset--maybe even with lighting coils & real lights. Or DT400 as mentioned above. I know your MX is small internal rotor--but, heavy flywheel makes a nice lazy but powerful motor if that makes sense.

@ Gary Dean, In the States, Washington. That is a very gracious offer. I do not know if it will fit since the parts lists are different for your and mine. Yours is an outer rotor, mine is inner. It looks like it could, but the line drawing does not reveal much in the way of connectors, wire colors etc. What I do know is that many '73 and '74 parts are interchangeable, so it is maybe a small chance it could work. It would be really good if somebody could chime in, if they have any experience in the matter. If by chance it does fit, what would you like for it? Please PM me the answer.

@ RT 325, I am seriously considering that. I really wish I could go to the good old fashioned points and condenser set up, but I think that takes a new crank half for the cam.

This is simply a curious question. It is based on the good number of used mx250 and 360 stators I see on ebay. Since the guy at the bike repair shop says that the parts go bad because of old age, it make me wary buying a stator that is 48-49 years old.

The question is, how many bikes out there you guys have that still have the original stator and/or CDI box. Or even if it was replaced with another part that is the same age but perhaps changing it out for an outer rotor or a points and condenser setup that is the same age as your bike(s)?

You don't need a new crank.  Cam is in flywheel.