Have a DA 100 with about 80 flights on it running 80:1 Amsoil.
Was flying this morning first flight engine ran flawless like always, second flight engine fell flat on it's face. Roll to knife edge engine almost quit running was at full throttle, roll inverted engine starts to sag went into a hover and engine quit all together runs great on straight level flight.
Checked spark plugs they were okay and check compression on cylinder heads good and strong wants to blow finger off of cylinder.

What do I need to check for?

Rich