Authentic Mercury Marine part 851903A1 Needle Kit, a needle/seat kit for Mercury MerCruiser carburetors, superseding FK10107-3. This genuine factory kit replaces the needle valve and seat in the carburetor to restore proper fuel metering and sealing, helping maintain reliable engine performance. Sold as a Mercury-MerCruiser replacement part and available through authorized distributors and retailers, this kit carries the 851903A1 catalog number for ordering and cross-reference.
