fuel/air mixture

I have an Edge Performance 912EFI with 155hp but the readings should be similar.

Your EGTs are probably close to 12.5 A/F ratio.

I have my A/F ratio set at 13.1

I climb out with EGTs of 1530 and cruise at about 1470.

There a many factors that effect EGTs but, at 1420 you’re in a safe zone.

Ed

You guys may be playing with fire. An expensive fire. It's not all about running for the next 10-100 hrs., but making it to TBO and under the right conditions detonation.

Roger, I was hoping you would chime in as I have learned a wealth of information from reading your posts... although I am still a novice.  My goal is to extend engine life and I have tried to be meticuous about balancing the carbs.  I feel confident with the carb balance as it is a defined process.  However, when it comes to setting the needle height and jet size I do not feel very confident.   This is why I am asking if EGT readings could be usefull in tuning the carbs?   I am debating installing an O2 sensor so I can be more sure I have my carbs set up correctly.  However, I do not see a lot of Rotax owners with O2 sensors so I am wondering what is the best way to precisly set my needle height and jet size.  When I was tying to fine tune the engine in the idle circuit, I noticed small changes in the idle adjustment screw would show in the EGT readings.  I am thinking some of my resoning may be off so please correct me where I am wrong.

There's been a thread going on the TeamKitfox forum for several months about tuning the carbs on a 912ULS with the help of an AFR gauge.  You might find something useful in it.

https://teamkitfox.com/Forums/threads/12150-Precision-tuning-the-Rotax-912-UL-ULS

I agree there is no exact instructions on   this. Rotax recommends normal EGT to 1470 but when we try to achieve that mechanics tell is no 1200 is fine.  Why does rotax recommend 1470 as normal if people like it lower? One experienced guy tells me absolutely NOT you should be averaging the 1470 and not lower and that is good for the engine.

What the heck is the real correct answer?