CATEGORIES HOME RLV 1 5/16" Exhaust Silencer, Mod/Open Item Number: RLV4106 Price: $50.79 Add to Cart Description This muffler fits a 1 5/16" OD 4-cycle pipe, and is used for limited, modified, open, and Tecumseh Star (10HP) classes. It has the large square holes in the baffles and is not legal for any stock AKRA, NKA, WKA, or IKF classes. Accessories Muffler Clamp, Heavy Duty, Stainless Steel Universal Header Brace 17"