RE: help with fuel for os91vrdf
For ducted-fan engines, the oil content should be AT LEAST 22%. 24%-25% is better. Lower oil content fuels will cause the lower end of the connecting rod to seize to the crankshaft. The high RPM of the engine makes it difficult for it to get enough lubrication with lower-oil fuels.
Wildcat Ducted Fan fuels have 23% oil and 5% or 10% nitro. You don't need high-nitro fuels for good ducted-fan operation.