Yamalube 10W30 4 Stroke Oil Change Kit - Yamaha F30-F70 Outboards This Yamalube kit contains all you need for an oil change on your Yamaha 4 Stroke Outboard Engine. Yamalube 10W-30 is designed for maintaining viscosity in 4 stroke outboard engines in marine environments. NMMA FC-W certified, this oil features rust inhibitors that helps keep you moving smoothly and increasing engine life. Yamalube utilizes anti-friction protection to help promote efficient fuel economy and increased performance.