Yamaha - 10W30 Marine Full Synthetic Oil - 55 Gallon - QBL-10W30-FS-55. Protect your Yamaha outboard with a full synthetic marine oil built for real-world, on-the-water performance. Yamaha 10W30 Marine Full Synthetic Oil is engineered to maintain consistent lubrication under heat and load, support cleaner engine operation, and deliver enhanced corrosion protection in humid and saltwater environments. Supplied in a 55-gallon drum, it's an ideal solution for high-volume service operations, marinas, and shops that need reliable oil on hand for routine maintenance and bulk use.. 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 elevated operating temperatures. Marine-grade corrosion protection for storage and harsh conditions. Supports cleaner internals by helping reduce sludge and deposits. Container Size: 55 gallon drum. OEM Part Number: QBL-10W30-FS-55. Ya