We just cut lower branches off our pine tree plantation, 2 hours straight of limbing them using Amsoil synthetic Saber 2 cycle at 100-1 in my Pulon. I never saw a bit of smoke at all and it purred at idle and revved full throttle all of that 2 hours. Great stuff.
I would find a station that sells ethanol-free 90 octane fuel and use it.
Then I would use only oils that meet ISO-L-EGD or JASO-FD rating. These are oils from Echo, Husqvarna, Red Max, etc. Read the labels and make sure they have the 'FD' in a little box on the label to ensure they have been certified.
If you haven't already done so then consider replacing the fuel lines on your equipment with yellow tygon line. This will prevent future issues such as line deterioration and tube splitting. Following these measures and using fuel stabilizer in the off season will practically guarantee you trouble free operation for the next decade.