No spark

I was on the way home and my bike stalled on me after a climbing a hill, no big deal. It started up again with a little extra peddaling then I let it idle for a few minutes then it died again and wont start. I dont have any spark. I disconnected the kill switch, checked all the wireing, tried a known to be good plug and nothing. I walked it home (had a flat to boot after peddaling for a mile) and I got some on the resistance readings for a good coil and magneto from the site here. I dont know if my ohm meter is very good, I got some readings that matched and some did not register at all. I put a known working coil (off my sons bike) on and still nothing. I am getting power to the blue wire to the cdi and the white wire while cranking the engine over but nothing at the spark plug. Is it possible they both went bad? What would've caused this? Engine only has 200 miles on it and has never seen any water. I inspected the magneto and it looks fine but how do you tell for sure, it is putting power out. I guess i will have to order them both but is there a definate way to check these electrical components?

I already had a good wire and ngk plug in it, tried switching back to stock and tried another ngk and another wire. Nothing. I will try the known good magneto tomorrow. I did find some ohm specs on here and both the mag and the cdi have some of the readings but missing some also- no reading at all. Is it rare for them both to go out for no apparent reason? My son and I were coming back from a 20 mile ride and got to the top of hill to get back on the pavement (we were running down a fairly rough dirt road a few miles- not much air or anything but...) when it stalled, restarted to die a few minutes latter then nothing! I've already ordered replacement parts but still want to determine which one is the culprit or both. Just seems strange that both would go out for no apparent reason!
ps to Pablo-- thanks for all the help with my bottom bracket ?'s! (would've ordered yestarday but the kid had a date and needed a cash advance!).

no I have not tried just holding the plug to feel for a little something, but I am gonna have a hard time sleeping tonight if i dont! I did try other spark plugs though and could not see any spark at all. The plug really didnt look fouled when i first removed it either. I just dont know which one , mag or cdi, is bad or what the heck is wrong! I have such a hard time letting this go to wait for parts!
Thats also why i ordered two of each- gotta have back up because i have no patience!

Well I went and ran around with the bike holding the spark plug, I felt a little silly and no spark. I put a light tester on the white wire and I can get it to glow a little, tried on the blue wire and no light but earlier i was getting a small reading with a voltmeter. Just dont get it-have power coming to the cdi- no spark- put on good cdi (from sons bike and it runs) and still no spark. Well I'm tired and hungry, so tomorrow I'll swap in the known good mag and see what happens. I wish I could get these parts locally! Just hate not having my motor bike running!

The ohm readings on my magneto
black to white should be 2 ohms but i have nothing. Taking reading with the mag out of engine and no black wire- probe going to where the black wire would connect. No matter what scale i put it on nothing at all. Is this the problem?

blue to white I'm gettin 338 ohms. Thats a good reading from what i understand.

At the cdi I am only getting a couple readings.
pos lead on blue, neg lead on black- no activity-good
pos lead on black neg lead on blue Sporadic reading and meter has to be on 20M to get anything should be 130-150
pos lead to sparkplug,neg to blue wire same sporadic reading
pos lead to sparkplug, neg to black wire 2.3 should be 2.5-2.7

On the way out the door to check the known good mag with the cdi. I dont know if I trust my meter as it is a cheapy from autozone.

so the cdi is still good. Strange that i dont get the ohms readings. So now to try and determine what happened to the magneto. Maybe to low a power output to create a spark-weak magneto? but it shows 338 ohms? shows nothing though to black wire. I'm glad i have another set up (working bike) to figure this out. Still confussed as to what caused the failure. I did notice it was starting as easy as it used to, do these magnetos get weaker with time- less than a month?

Well I got the magneto fixed- little wire on the wrap going to ground was soldered poorly. I have 2 cdi's and 2 mags on the way though! I really have to work on my patience! If anyone near mesa az needs either of these Look me up!