48cc 2 stroke bbr tuning. Test magneto while in?

You really need to learn how to use a multi meter -- Your negative probe is on the 10 amps input.
Not sure how you got that reading as you are effectively shorting it out.

Positive goes to red (volt,Ohms,1 amp)-- you have this right = red

Negative goes to black (common) -- you have this wrong = black

I am guessing that your original CDI probably works

YouTube is your friend here there are probably a million tutorials on how to properly read OHMS and volts on a multi meter, I got faith in you try again this time do it right.

Post a close up picture of your meter without the probs on and I can edit the picture to show you the right setting and where to attach the probes and what scale to use.

EDIT: Hooking up the meter wrong in the ohms setting and checking resistance will not cause any damage but checkg volage the way you have it will blow the fuse in the meter, Some meters have a protection circuit yours is cheap so more than likely not. you may need to buy a couple of fuses