What is the main danger from using a weak mixture at a high power setting?

Using a weak mixture at a high power setting primarily leads to detonation, which is a critical concern in engine performance. When the air-fuel mixture is weak, it can result in excessive combustion temperatures and pressures. This occurs because the combustion process is less controlled, causing the fuel to ignite prematurely or unpredictably. Detonation happens when the mixture ignites spontaneously due to these high pressures, rather than from a controlled spark from the ignition system.

Detonation can cause severe engine damage, including piston damage, cylinder head warping, and overall engine failure. It is especially risky at high power settings, where the demands on the engine are at their peak, and the likelihood of knock is increased. In contrast, low cylinder head temperature and low fuel pressure are typically not direct effects of a weak mixture under high power, and while pre-ignition can be a concern, detonation is the more substantial danger associated with a weak mixture in this scenario.