Have spent some time chasing an erratic egt gremlin.  First indication was a noticeably lower egt than any other cylinder - chts looked normal.  After a few more flights the egt started out low and on climbout went very high (1400+).  Exhaust pipe inspection looked same as the others.  Previous egt issues were fixed with a new sensor - all good.  Went through 3 sensors, swapped leads, replaced entire egt wire/connectors to the pin in the DB25 (dynon ems/hdx).  Dynon did an outstanding job working with me the whole time.  Ultimately swapping a refurb ems to check the system.  No change - same lo/high indications.  Closer inspection revealed a break/crack in the sealant on the induction pipe from the carb manifold to the cylinder.  Removed, cleaned, reseated/sealed pipe with Jabiru recommended Loctite gasket sealer #2.  Check flight today - back to normal egts!!!  Lesson learned - ensure to closely inspect the induction pipe seal.  There is an O-ring in the manifold, but the seal can make a noticeable impact on the fuel/air mixture to the cylinder and the resulting egts.

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Thanks for posting this, James. Stuff like this is very helpful to folks coming here looking for answers/clues.

Awesome post.   Thanks I will know to be watching for this.  

Thanks for posting this! I've been chasing the same issue on my Gen3 cyl 5 and 6.  Previously, I hadn't gone all the way back to the manifold to check for leaks. (didn't see any) Did this time, Took a deep breath today, pushed the throttle forward, and Tadaa! No more issues. Slowly working the bugs out of my recently purchased 601. And having fun doing it.   

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