Mercury - Weber 4-Barrel Carburetor Repair Kit Carburetion System Precision Marine Components 8M0120197. Overview. There's something familiar and almost comforting about the way a MerCruiser 4.3LH or LXH engine sounds when it's running the way it should. The steady rumble at idle, the smooth pull onto plane, the consistent power when you're carving through open water-those moments remind you why you love boating in the first place. But when a carburetor starts to wear out, the signs creep in slo