Jim, Thanks for pointing me in the right direction. I found the location of the EGT probe on page 10.1 of the Rotax 912S manual and the distance from the flange is stated as 2.76". It doesn't seem to say anything there about which cylinders to monitor. On page 21.1 of the installation manual it does mention that CHT should be monitored at cylinders 2 and 3 (one in front and one in back), in which both ports have a temp sensor installed. However, there's a CHT sensor port location on every cylinder head so this gets back to the basic question on what everyone is doing with CHT and EGT monitoring - Is the most common practice and/or recommendation to monitor CHT and EGT on all cylinders or just specific ones (#2 and #3)?