My start with two stroke engines as many years ago, it was a 2hp Seagull and that ended up as a swop for a rubber duck dinghy in Rio do Janerio, we needed to get ashore, having an outboard and no dinghy was not going to work?
The mix shown in the open container has gone a dark brown, why? I used some old Mobil marine grade 2 stroke oil I had, its about twenty years old, does it go off?
A friend has recomended I use Shell Nautilus premium outboard oil, as he has mixed that with unleaded petrol and stored it for many months with out any degrade.
Shell Nautilus is dyed green, so matches the unleaded fuel a little, this helps with later identification of the mixture, the reverse side of the five litre container has the 10:1 British Seagull ratio and also the date I mixed it writen in a black koki pen.
I will let you know how I get on with this Shell oil.