9N won't start unless I jump it, then runs for 20-25 minutes and then dies. Then I have to wait a little bit and jump start it again.

Could be a fuel problem , check for a blocked fuel filter .

What about Idling? Will it just run?

Sounds like your solenoid is going bad... easy fix..

You could have a bad cell in your battery, autozone or advanced auto can test this for you free of charge. there are other things that can be causing this as well like an exposed power wire grounding out on the frame of your car or an amplifier that powers your subs going bad as well.. best bet is to start with the battery!

Check the bottom of the carburetor for a little solenoid. If it has one, the battery may be dead enough that it can't keep the solenoid open causing the carb to shut off the fuel flow causing the unit to die. The easiest way to check if it works is by turning the key to the run position and listen and/or feel for the solenoid to click. If it clicks it is working and there is another problem, if it doesn't then replace it. I recommend having the battery tested or replaced too

If you need further help, I’m available over the phone at https://www.6ya.com/expert/kelly_69a0cf1b13789df1

you may have a bad ground, or the ignition switch needs to be replaced.

check to see if your loosing spark when this happens the coil maybe failing

check the safety switches

Put a new fuel filter on its pluged up. if that dosent fix it do a fuel pressure test.

Try changing your TSP Throtle Position Snesor