Yamaha 10W30 Marine Full Synthetic Oil (1 Quart) - QBL-10W30-FS-12. Protect your Yamaha outboard with a full synthetic marine oil built for real on-the-water conditions. Yamaha 10W30 Marine Full Synthetic Oil helps maintain stable lubrication under heat and load, supports cleaner operation, and adds corrosion protection for humid and saltwater environments. It is an ideal choice for routine maintenance when you want smooth performance and dependable protection from start-up to shut-down.. Key Features. Viscosity: 10W-30. Type: Marine full synthetic outboard engine oil. Formulated to help protect against wear during high RPM operation. Helps resist thermal breakdown in hot running conditions. Marine-focused corrosion protection for storage and downtime. Supports cleaner internals by helping reduce sludge and deposits. Bottle Size: 1 quart. OEM Part Number: QBL-10W30-FS-12. Yamalube 10W-30 full synthetic is recommended for use on all outboard engines running 10W-30 engine oil. Performanc