I don't want to give away my age but I've been mixing my own 20% castor zero nitro fuel for 50 years now and so far I've never found an engine that won't run perfectly well on it. Most engines can be modified to run even better by raising the compression but it's not really necessary. Take the advice given by others about using a hot plug but most are using these anyway even with nitro. If you're used to using fuel with a fair amount of nitro then the needles will seem more sensitive but this is mainly because the engine won't use fuel as fast (longer flights on the same size tank) so the needle needs to be wound in more for a proper tune and less movement is needed to go from rich to lean.

Don't use less than 20% castor with zero nitro because with the low fuel consumption it needs this amount to flow enough oil through the engine.