The Petrol/oil mix will not really affect the starting unless you are referring to the gunk in a 2 stroke carby that is left behind when the petrol evaporates.
Just to get the thing fired up 25 : 1 would be fine, it wont be doing any work when you start a tune etc, if it was mine I would be cleaning out completely the fuel system, from the tank to the carby and everywhere in between.
Once you get it running and carby etc tuned you might then want to check point gap, as NormK has said above and I said in my first post it would appear you have a fuel problem (not necessarily the ratio you use to start), 2 strokes that have been left for a while do gunk up.
Beech
