I don't know the Stihl ratio but the gas/oil mix for my Husky's (50:1 I believe but that's from memory) is just a very light blue.
Also... gas from flooding can kill a new spark plug.
Try a spritz of ether right into the cylinder via the plug hole. Put the plug back it and rip the cord. If it STILL doesn't even cough, it about has to be compression.
It is 50:1, I downloaded a PDF manual to be sure. I bought premixed fuel from the Home Depot. It is A) 92 octane B) ethanol free C) uses synthetic oil to a 50:1 ratio (you can buy 40:1 as well). I did this as we have not ethanol free gas available, and for small engines I avoid ethanol fuel like the plague!
It would not start with Ether sprayed into the head and the plug quickly installed.
Tomorrow at work I'll pull the muffler/exhaust back off and take a good look at the piston/cylinder for damage.
