What is the oil capacity for a 1981 Seca 750?

The oil capacity for a 1981 Yamaha Seca 750 is approximately 3.5 quarts (or about 3.3 liters) when including the oil filter. It's important to ensure that you check the oil level with the bike on level ground and after the engine has been warmed up for accurate readings. Always refer to the owner's manual for specific maintenance guidelines.