RE: a few questions following the MINARE's maiden flight
You can check behaviour by filling the tank with for example 20 % and adjust the neelde valve full power, nose up. Than stop the engine and fill the tank 100 %. Start the engine again and observe the RPM horizontal. When this is much lower than with the level of 20 % you can think about swap the tank, if it's possible!
Important still can be the way the pipe is tuned!!!! Normally the length is some longer than for max rpm is needed!! When your pipe is short or even too short that will have influence too. under load it drops out of the curve, but I am not familiar with your brand. Also experience is too long ago for me!.
Cees