Here's some additional information:
* Type: Use a mineral-based oil for older bikes.
* Quality: Look for API SG or higher for good performance and protection.
* Capacity: The XS1100 holds approximately 4 quarts of oil.
* Oil Filter: Always change the oil filter with each oil change.
Note: Always check your owner's manual for the specific oil recommendations and specifications for your 1980 Yamaha XS1100.