What kind of oil do you put in the crankcase of a 1977 it400?

For a 1977 Suzuki IT400, it's recommended to use a high-quality 2-stroke oil specifically designed for air-cooled engines. Look for an oil that meets JASO FB or ISO EGD specifications to ensure proper lubrication and performance. Always check the owner's manual for specific recommendations and oil capacities for optimal results.