So your running
both echo at 50:1 AND marvel mistery,
AT 20:1!!! AND fuel stabilizer? WTF????
Why not just get Some non-detergent 30W and run it 20:1
P.S. making your own E10 free from corn fuel is a foolish (fuelish?) endevor. The ethanol effects octane rating and you won't have a clue to how much LOWER it is without the ethanol. Besides that, you are are going to have to dry the fuel chemically (sodium or magnesium sulfates) or add drygas (isopropanol) to get rid of the "wet" ethanol free gas.
I used to teach analytic and organic chemistry and we did fuel analysis by GC/MS, and Ive purified many hydrocarbons.