RE: OLD SCHOOL O.S. max .30 R/C
I think the Fox or Sig 25% all castor oil and 10% nitro fuels would work well. Us a Fox or K&B idle bar plug and you will be set to go. I would guess a 10-5, 10-6, or 9-6 prop running from 10,000 to 12,000, but I have never ran this engine so its just a guess.