As a good rule of thumb, an r/c engine should run between 175-215 for best longevity. The IR temp sensors are so-so for readings as have been pointed out.

Here is an old-fashioned method that works well - if the head is hot enough to sizzle water, spit etc on - ITS TOO HOT (i.e. above 220)


It is not uncommon for the engine to go above 220 on break in, but it should fall off with a richer mixture an/or more oil.


My DA100 runs consistently at 184, my 3W-75 runs at 194 and the ZDZ80 ran at 205 - all measured with an RCATS telemetry unit on the plane and in flight - thermocouples installed under the plug, and on the cylinder base bolt (case temp and head temp)

DP