eli5 What’s happening when an engine stalls from low RPM?

Question

eli5 What’s happening when an engine stalls from low RPM?

In: 21

Answer 1

If you think about peddling a bike, you push your foot down on the peddle on one side, it brings the peddle around on the other side, so you’re always able to push: either with one foot or the other.

Now let’s say you’re peddling up hill, and it’s getting harder and harder to push, and at a certain point, although you manage to get the peddle part way around, you don’t quite clear it so that you can push with the other foot.

Because you’ve lost the momentum between the peddles, you can’t peddle anymore, and your bike stops.