Mercury Clamp — 54-8M0214964 (sold individually)

Barely the size of a quarter yet tough as your outboard, this constant-tension clamp locks fuel, air, and cooling hoses tight on a wide range of Mercury DFI, EFI, and Pro XS engines from 115 hp to 300 hp. Formed from spring-tempered stainless steel and finished in Mercury’s yellow-chromate coating, the band flexes with heat cycles instead of loosening, so the connection you torque today stays leak-free all season. At just 0.01 lb and under an inch long, it slips onto tight rigging runs without adding bulk or rattling against cowling panels.

Why boat owners keep a handful on board:

• 15.3 mm working diameter suits common ⅜″ fuel and bleed hoses on 1.5 L to 3.0 L blocks.

• Constant-tension spring design maintains clamping force through expansion, vibration, and wide-open throttle runs.

• Marine-grade stainless shrugs off salt spray and ethanol blends—no rusty set screws or stripped worm gears.

• OEM fit replaces legacy 54-856880 and other clamps in fuel-pump, air-hose, and rail assemblies—no guesswork.

Swap a tired clamp during your next impeller or filter service, and cruise away knowing every drop of fuel and slug of cooling water stays exactly where Mercury intended.