I was indeed thinking carb ice, not for the OP, the one at Wellesborne. Taxi-ing on wet grass will get most engines a good dose of ice in humid air, and at low ( one hopes ) RPM. I have had this with an O-320, and more than once with a Limbach ( aka Volkswagen ) in an SF 25. Now that one is REALLY known for icing up. :-)
Last edited by Piper.Classique; 12th Jul 2014 at 19:54.
Reason: clarification