C172SP fuel injected IO-360.
its ancient mechanical fuel injection fed by....an engine driven pump and an electrical pump for critical phases of flight.
So mixture idle cutoff - fuel selector off and no more fuel to a fire.
Don’t complicate things.
Unfortunately this is where instructors can damage their reputation and their believability suffers.
Don’t make up stuff that isn’t there.
Once had an instructor for a jet recurrent that had come up with a sim scenario that eventually had you turn off an electrical bus that powered the engine fire extinguishers and then he gave you an engine fire on an ILS below minimums.
We fell for his trap and landed with a fire we couldn’t fight.
Never mind the chances of these 6 steps ever lining up being 0.01 x 0.01 x 0.01 x 0.01 x 0.01 x 0.01 per 100.000 flight hours.
Possibility doesn’t equal probability in anything in life including mechanics.
An examiner will hold you to a well known and well published standard.
Every instructor has their pet peeves but made up stuff shouldn’t be one of them.
I was once called over and scolded by an examiner for teaching a student a technique which wasn’t in the flight manual and which he promptly demonstrated on his flight exam.
Lesson learned.
Now..I consider it very good practice to theorize about certain events and their likelihood and technique with fellow students, more experienced pilots and instructors and students.
Just a healthy enterprise and good exercise in systems knowledge and understanding.
Reviewing accident reports under guidance is another good way of learning.