I moved to Europe last year and have been racing in Europe (Denmark) this year.
I lost 3 podiums with the EVO engine just this year because of various issues. It seems that I finally found the root cause.
Everything would run perfectly the first half of the race day during practice, qualifying and perhaps also the first heat race.
Then the (DD2) engine would start to pop or “4-stroke” and my race was over. I was running the Rotax Lithium battery with my Mychron 4 with GPS connected to it as well.
I have run this combination for years in the US (prior to the EVO) but apparently the EVO ignition/power valve sucks more power and the ridiculous Lithium battery with only 2.5AH cannot keep up.I even bought a $120 charger and charged between races.
Looking at the data the voltage never drops below 12.8V so therefore it was almost impossible to find the problem. I went back to the old style battery and the problems disappeared. I have since heard a lot of people complaining about issues with the Lithium batteries.
I also just heard, that Rotax already got an upgrade out for the upgrade (someone said clutch?) The EVO power valves are not working properly so last week in Germany Rotax was running around moving the spring outside the bellow again as well as using the sucking side (as opposed to the pressure side) tube connection. This should make the power valve work.