Maxima (23505) Castor 927 2-Stroke Premix Racing Oil - 5 Gallon Pail Castor 927 is a unique blend of highly refined castor oil, a specially prepared synthetic and an additive system that reduces carbon and gum formation and provides excellent rust and corrosion protection Castor 927 also contains an exclusive additive that keeps power valves cleaner and working properly Castor 927 is biodegradable Castor 927 keeps on lubricating; where other lubricants turn to carbon or vaporize, and provides extra protection on cylinder walls, bearing journals and other critical areas at temperatures much higher than other lubricants Castor 927 is ideally suited as a premix for both leaded and unleaded fuels