Auto ignition temperature of castor is 450 degC. I don't think that castor is having any effect. We know that the castor isn't burning in our engines. It can't vaporize in our engines. It may work in an injected diesel where vaporization is mainly done by the injector. Cetane rating describes the ignition property of fuel. If it's not buring what difference does it make?

The castor will probably settle out at lower temperatures in a straight kerosene mix. I had this problem when i was running my diesel this spring with lower ether content mixes. With enough ether the castor would stay in solution.

Did I read the your Youtube right in that with 20% amsoil mix the engine would not throttle at all?

Greg