Thank you for the advice, this is all helpful to me since I have no knowledge on anything with electrical stuff. I have an NU50M that is running so I have been using that to kind of take parts and test it on the NU50 that I have that doesn't have spark. I was kind of in a rush today and wanted to start testing some parts so I did a few minor things. This is what I've done so far:
1) Brand new spark plug and gapped it
2) Swapped in a tested working spark plug boot (just the boot, not the wire or anything else)
3) Swapped in the kill switch from the running NU50M to the "no spark" NU50. The running NU50M has an electric start so the kill switch wire bundle does have an additional wire in it since the "no spark" NU50 doesn't have electric start, but I don't think it matters since it appears the electric start wire is really not part of the whole kill switch wire bundle.
4) Swapped in an untested ignition switch from the running NU50M. Just realized that the running NU50M is hot wired and doesn't even need its ignition switch on to get spark. So the ignition switch may not be working so I may swap the NU50's original ignition switch back in
5) Cutt off 1/4 inch of plug wire to the spark plug so it has a good connection to the spark plug boot when reattached. Didn't cut off 1/4 inch from the other end yet since it seems hard to get space to get my hands up in that space to remove it.
Still no spark. So what do you guys think I should attempt next? I like the idea that Michael gave of using a volt meter to test the wire to the secondary coil from the ignition and try turning the motor over to see if electricity is even being sent to the coil that powers the spark plug. I would have done this already but not even sure how to do it 100% right, so I'll have to take some photos to make sure I'm doing it right and post them here.
Or do you think I should swap in the ignition coil from the running NU50M into the no spark NU50? Or should I swap in the CDI from the NU50M to the NU50?
Or do you guys think I should run some other tests of some sort to narrow down the area that is giving me trouble?
Thanks again, I'm honestly a bit overwhelmed with this stuff. I really don't have a clue what I'm doing