Quicksilver Serpentine Belt 57-865615Q07

Quicksilver Serpentine Belt

The Quicksilver 57-865615Q07 is a genuine OEM serpentine accessory drive belt engineered specifically for MerCruiser big-block inboard and sterndrive engines. As a direct factory replacement, this multi-rib belt ensures correct rib alignment and secure pulley grip, maintaining reliable power transfer from the crankshaft to critical engine accessories including the alternator and seawater pump. Proper function of this belt is essential for both the charging system and the cooling system on equipped engines.

Commonly fitted to late-1990s through early-2000s MerCruiser V8 big-block applications, this belt is compatible with a range of engines including the 454 MAG MPI, 454 MAG MPI Horizon (Gen VI), 7.4L MPI, 502 MAG MPI, and 8.2L MPI MIE. Most applications fall within the 1998–2001 engine serial range. Always verify compatibility using the engine serial number, as MerCruiser engines with similar displacement may require different belt lengths depending on accessory configuration.

This part supersedes several earlier Quicksilver and MerCruiser part numbers, including 57-861050, 57-8638767, and 57-865615007. The aftermarket equivalent is Sierra 18-15103. The belt has an approximate length of 2467 mm (96.75 in) and weighs 0.53 lbs.

Key Features

• Genuine Quicksilver / Mercury Marine OEM replacement part
• Multi-rib serpentine design engineered for proper rib alignment and pulley grip
• Transfers power to the alternator and seawater pump for charging and cooling system operation
• Designed for high-load marine engine environments
• Compatible with MerCruiser 454 MAG MPI, 454 MAG MPI Horizon (Gen VI), 7.4L MPI, 502 MAG MPI, and 8.2L MPI MIE engines (approx. 1998–2001)
• Supersedes part numbers 57-861050, 57-8638767, 57-865615007
• Aftermarket equivalent: Sierra 18-15103
• Approximate length: 2467 mm (96.75 in); weight: 0.53 lbs