2kpounders: The local artic cat dealer here runs Schaeffer in all his shop oil changes, he used 20w-50 racing prior to Schaeffer coming out with the vtwin mc oil which is meets JASO MA so I would not hesitate to use it, but be aware it is not 100% group IV basestock but a blend, which for all intensive purposes is likely OK. Many synthetics are blends anyway, I don't believe Mobil, Valvoline, or Royal Purple are blends.