After I hit the 170 flight hour mark I started to see some fluctuations on my number one cylinder EGT(exhaust gas temperature) gage. It started with slow but ended up showing an extremely high temp them going to zero. This happened on two separate flights. On the second flight the number three cylinder started showing similar signs.
So off came the edging cowl to inspect the probes and their wiring. First I checked all the wires for any signs of chaffing or cuts. Then the connections to make sure they were tight and intact. Last thing I did was to remove the number one probe from the exhaust pipe and bingo there it was. So I removed the number three probe as well and it looked the same.
Here is what they looked like when I removed them:
Luckily we have a Aircraft Spruce location an hour away. I looked up the part numbers and they were in stock so I made a drive down there and picked up four new probes. Figured I would replace all four since I was at it. Good thing because the other two looked similar to the first two. l
This photo is of a new one and you can see how the probe is supposed to look. Not sure if this is a normal wear pattern for the Dynon probes but will do a little research
After replacing all four probes and a quick run up on the engine we are back in business and indications are all normal.