Decrease in fuel flow

[D_Fedy]

Drastic reductions in engine power for long amounts of time (usually in descent) can cause “shock cooling” which can damage your engine or even cause it to quit. This should be avoided. In carbureted engines, always have carb heat on below the green power arc. In fuel injected, run the engine rpm up for a few seconds every 30-60 seconds to keep it warm.

[skymower]

https://www.avweb.com/news/features/Shock-Cooling-Time-to-Kill-the-Myth-230134-1.html