I guess I’m finding another reason for burning 2-cycle oil rather than sump oil injection. On my Velocity the exhaust goes out through the prop. It discolors the prop – not because of temp (I’ve measured that), and not because of carbon deposits – but because of brownish, sort of gummy stuff that I’m concluding is partially burned oil. Extended Running at low power on the ground, or after a long decsent, there is enough on there, and fluid enough, to actually streak outward a bit from centrifugal force.
It would help, of course, if the OMP setting was coupled to the throttle as in a car, so it would shut off when the throttle is nearly closed; but that is a complication I didn’t include on the plane.
I’m running Castrol 20-50, which is a great lubricating oil, but apparently it doesn’t burn real well.
Al