Sure, but the whole point of reducing the oil percentage in two stroke engines has been (since like 40 years) to reduce the formation of carbon in the combustio

Sure, but the whole point of reducing the oil percentage in two stroke engines has been (since like 40 years) to reduce the formation of carbon in the combustion chamber and - particularly - to have cleaner spark plugs (which imply better ignition) besides better combustion. Less oil in the mix (as long as lubricating is sufficient) is better. The traditional 4-5% is for mineral oils. Synthetic (totally or partially) oils can usually go on 2% (or 50:1) and in some cases as low as 1% (or 100:1). Modern chainsaws and similar are already at 2%, see (examples): https://www.stihlusa.com/information/how-to-guides/mixing-oil-and-gasoline/ https://www.stihlusa.com/information/how-to-guides/mixing-oi... https://www.husqvarna.com/au/forest/when-working/usage/how-to-mix-2-stroke-fuel/ https://www.husqvarna.com/au/forest/when-working/usage/how-t... https://www.amsoil.com/p/outboard-100-1-pre-mix-synthetic-2-stroke-oil-ato/ https://www.amsoil.com/p/outboard-100-1-pre-mix-synthetic-2-... Ignition in an engine for airplanes/drones/etc. is - obviously - much more important than in a common 2 stroke engine (chainsaw or similar), a "common" 2-stroke engine used in ultralights is the Rotax 582 (an earlier model was the 532) check its "limitations": https://en.wikipedia.org/wiki/Rotax_582 https://en.wikipedia.org/wiki/Rotax_582 The 582 has twin sparks (two spark plugs per cylinder) and runs on 50:1 mix: https://www.flyrotax.com/produkte/detail/rotax-582-ul.html https://www.flyrotax.com/produkte/detail/rotax-582-ul.html