RE: Adding castor oil
If I'm correctly informed the Coolpower fuel contains 17% synthetic lubricants.
If this is the case I can see no reason why it shouldn't work for ABC-engines.
All my engines (mostly OS, Saito and Super Tigre) are run on fuel containing 15% synthetic lubricant (Aerosynth) and no castor oil.
The exception is the ST 3000 which use only 10% oil. I have done so for the last couple of years and have had no problems whatsoever.
You can mix some castor oil in your fuel as a protection against lean running or if you suspect that your engines will operate at high temperatures (e.g. tightly cowled engines).
Do use some kind of after-run oil to protect the ball bearings against corrosion.
If you send me your e-mail adress I can send you a fuel mixing spreadsheet (MS Excel) that I ise myself when mixing fuel.
/Red B.