On Sunday, October 18, 2020 at 1:00:07 PM UTC-7, Graham Stanford wrote:
Just bought an ASK 14 motorglider and reading the flight manual
etc. The fuel required is noted as octane 80 normal gasoline mixed
with two stroke oil at a ratio of 20/1.

The chap that owned it before me ran it on normal unleaded with
shell vsx at a ration of 30/1.

I’m sure this is ok but I wanted to see what anyone else currently
uses?

Thanks

G
The oil to gas ratio is function of oil type and not fundamental to a 2 stroke engine design. The 20:1 ratio sounds like conventional oil and not synthetic. Most pure synthetics are 50:1. A down side to conventional oil is they burn very dirty with lots carbon buildup in the cylinder, ports and are very prone to fouling the plug Synthetics burn much cleaner though not perfect.
Buzz