Hi Harold
The FOX ABC sets that they ( i actually heard K&B made them) made are not fitted as tight as the aftermarket early ones that George had, use a minimum of 50% synth fuel with at least 25% total oil. run it 2 to 3 minutes at a time with cool down in between, Set the needle so it runs the cackle between a 4/2, NOT richer, then you can pinch the tube for a second to let it burst into a 2 cycle, after a couple runs, you can turn the needle IN to where the fOX will run in a 2 stroke , do this for 10 seconds the back to just between 4/2 stroke
8 to 10 runs should get it in shape to start flying. as stated do not run it very rich, nor very lean you want to bring it all up to temperature for breakin. I would highly recommend wood props to fly, and I would use a 10x4 wood for break-in
Randy