Because you voltage is a pulse a volt meter with a "TV" high voltage probe will not work.
Because you voltage is a pulse a capacitor divider will work.
Wish you were closer. I have some 100pF 40kv capacitors.
Series two caps to get 50pF 80kv, then a large low voltage cap (to ground) and you will see a much small pulse across the bottom large cap.
You don't have the pieces to make flyback transformers laying around. I have another plan.
I have taken copper tape and placed a piece around a high voltage wire. You can use tin foil.
This makes a capacitor to the inside conductor.
Measure the capacitor. 10pF. You probably can't so:
Add a 10nF 100V cap to ground. Now you have a 1000:1 divider. (but you really don't know the top cap's value)
Use a high frequency generator, sign or pulse, send a signal into the output of the ignition coil (what ever is making the high voltage).
If the generator is making 100khz at 10V then you should see 100khz at 10mV at the bottom of you divider.
You can add more metal in you high voltage cap or remove metal to get the divider ratio you want.
Or you can live with a 1357:1 divider and just do the math. (use the scope volts/div knob to set the ratio)
This will not measure DC but will give you a rough idea if the P-P AC on the high voltage wire.