Sierra 18-9420-3 SAE 10W-30 FC-W 4-Stroke Marine Engine Oil, 1 Gallon

Sierra 18-9420-3 SAE 10W-30 FC-W 4-stroke engine oil. Bottle size: 1 gallon. About Sierra. Reduces sludge keeping the engine cleaner for better efficiency. Describe the nature of the problem and its urgency (include pictures if possible).