Mercury Carburetor Gasket - 27-139376. A healthy two-stroke starts with a rock-solid seal between the carb throat and reed block, and that's exactly what this genuine Mercury Quicksilver gasket delivers. Die-cut from a fuel-resistant fiber composite, the dark-green sheet matches the four-bolt pattern on 75-115 hp inline-four outboards (plus 80 hp jet models). Its precision-milled port-narrow in the center, flaring to twin triangles at each end-mirrors the reed cage opening, so every piston pulse pulls a clean, un-turbulent charge into the crankcase.. Why it deserves a spot in your tune-up kit:. Exact OEM thickness compresses just enough to seal without distorting the carb body or reed plate.. Fuel-proof fiber blend shrugs off ethanol and premix oil, preventing blow-by leaks that rob power.. Laser-clean bolt holes keep alignment perfect; no trimming or "close enough" aftermarket slop.. Fits a broad lineup of 1990s-to-mid-2000s 75, 90, 100, and 115 hp 2-stroke Mercs-single carb or triple