I do beleive is break in needle valve and oil related, I did the same as FBW, broke in the engine with 23% oil, but 2.5Lts of fuel, then break in needle still open fly.
I have to try the YS fuel I got when weather colaborates, and that has 10% oil, thatīs why I burned so much 23% first. I have seen the same issue with a 185 Red that had the break in needle valve closed, and failed around 40 flights, as I investigated the motor, found the bushing rotated due to heat closing the lubrication orifice causing it to melt on the cranckshaft pin.

Will see how mine does on low oil.