I agree with JeffH. You can mix a gallon of methonal with the 10% you have and that would cut you down to 5% nitro. You would have to add some castor oil to get the oil level back up to 20% but you should not have a problem finding methonal or castor where you are at.

I fly my Moki's on no nitro and 15% oil. The 20x8 prop is a better break in prop for the Moki.

tonyc