A-B1691493-AI LINER-PORTOne New Aftermarket Replacement Port Liner Fits Briggs and Stratton Small Engines This aftermarket replacement port liner Fits Briggs and Stratton (B&S) small engines used in a wide range of lawn and garden equipment. The port liner is an internal engine component that lines the intake or exhaust port area of the cylinder, helping to maintain proper engine efficiency and sealing. Replacing a worn or damaged port liner restores proper engine