my local hobby shop doesnt carry Byron's fuel anymore,I have about 3 gallons of 20% 12% oil ran through my lrp zr30 engine and it runs great...all they had was 20% 14% nitro fuel...he said it isnt gonna hurt anything to run a higher oil...do i need to find fuel with the same oil or am i gonna be ok...i have never changed fuel in the middle of running before