I would not use 10% fuel in the OS.91. Wildcat 5% jet-a is the best, but sometimes hard to find. PowerMaster makes a ducted fan blend with 5% nitro and 23% oil content that is a castor/synthetic mix. I have a gallon , but have not tried it yet.
Install the engine in your jet and run it a little rich for a half a tank or so and go fly it.