From our first flight training lesson we were taught that carbureted engines are susceptible to the formation of “carb Ice” and it can occur at anytime and at any power setting…even at high-cruise power settings, but not always. The potential for carb ice even varies among aircraft types — Piper and Cessna are prime examples. That’s part of the dilemma: The “unknown.”
Source: general aviationCarb ice: A known unknown