Exhaust Flapper Valve & Clamp Kit – Fits Inboard/Stern Drive (Replaces Sierra 18-4458, GLM 89260, Mallory 9-44002) 15HP and is less likely to

and is less likely to mark your hull

The included gaskets are critical for creating a leak-proof seal between the manifold and the transom assembly

and gaskets as provided in the kit

The most common signs are engine overheating

the registration numbers must be at least 3 inches tall

Exhaust Flapper Valve & Clamp Kit – Fits Inboard/Stern Drive (Replaces Sierra 18-4458, GLM 89260, Mallory 9-44002) 15HP and is less likely toProduct Details This Exhaust Flapper Valve & Clamp Kit Fits 5" & 6" OD Exhaust Pipes is engineered to prevent water from entering the engine through exhaust thru hulls during low speed operation, stopping, or reversing. It is designed for a broad range of inboard and stern drive applications using either 5 inch or 6 inch outside diameter exhaust pipes. It serves as a direct replacement for Sierra 18 4458, GLM 89260, and Mallory 9 44002. Installs