Engine issue on takeoff

It doesn't sound like you are making full power before the engine stumbles. What is your Max static RPM?

You need to download the data from your Dynon as it will provide you information regarding the engine parameters during the time of the event. Important things such as fuel flow & fuel pressure will need to be evaluated.

Also, Where is the mechanical fuel pump drain line routed? Do you have it in a neutral pressure zone? Take pictures and upload them. If the drain line is routed into the slipstream or in a vacuum (negative pressure zone) it can have a direct effect on fuel pressure. This issue only appears during take-off or a flying condition and won't necessarily be recreated during ground runs.

Have you looked at the filter finger screens in the wings tanks?

Open float bowls and look for contamination. Look to see how much fuel is sitting in the float bowls (should be full). Check your floats and make sure they weigh below 7Grams together. Check for any blockages of the main jet. 

Open Gascolator and inspect for contamination. Check the fuel for water

And by ALL means, do not fly the aircraft until the issue is resolved!  

Seems like a fuel system issue.

Yes, it seems like fuel starvation. Do all the above and also check if the fuel tank vents are free. 

Hello and thanks everybody for the input so far.

Today my mechanic did the first steps in the investigation:


1) Spark plugs: Dirty, we changed all of them.

https://photos.app.goo.gl/FCBgu6razKGMTsTK6

2) We looked into the cylinder: No damage from potential detonation.

https://photos.app.goo.gl/zhhho6WCFMtP52DS7

3) Gascolator: clean.

4) Carburetor:

Left side: One float was lower than the other.

https://photos.app.goo.gl/D7vkeF8mQ8snAi4c8


Right side: Float bowl was connected with piece of rubber to the heat shield underneath (why?):

https://photos.app.goo.gl/THHMjWpXqvwy2LWv8

https://photos.app.goo.gl/f5f9cGWWWUgM3CLHA


5) We then looked at the blackbox data at the time of the incident (at second 30) and observed EGR temperature on the right to plummet.

https://photos.app.goo.gl/HFFD4v5S8GAEGmgRA

Does anybody have any thoughts on a root cause?

...howdies (new member) & a yowser !  Good on you, watching the nose & bringing it round, but not too fast ... much as i trust my little 912 (E-Fox-A-240), i dont like flying over neighborhoods ...   

I hope you will upd8te us on what your fix entails, & hours on your eng. 

Heres a pebble for the thread;

I had a panel of flashing lights w/ the EIS indicating 0 oil P at climbout; ~ +250' at a class delta airport; i declared an emergency; flew a descending right pattern to the 45 entry downwind around the 1000' bars and landed noneventfully w/ the EIS now reading normal (?).  I fd a spade sensor connection loose on the sensor near the oil filter.  Probably need to solder it.  

hastas / john