Hi Andy,
I see you've cross-posted to a bunch of groups, hope you at least read this one. I've put old fuel in my chain-saw, and motor bike before with no ill effects. The nitro-methane burned cleanly, even though the fuel mileage was not as good. Nothing special has to be done to the timing unless you run the fuel exclusively. You just won't get as much power out.
The castor oil, on the otherhand, made a mess at the exhaust.
-Fritz