Mercury - Quicksilver V-Belt Engine Drive Component 37" Length 65607Q. Overview. The right belt keeps everything in sync - from your alternator to your cooling system. The Mercury Marine 65607Q Quicksilver V-Belt is built to deliver smooth, reliable power transfer for MerCruiser 3.0L Alpha One, TKS, and MPI EC sterndrive engines. At 37 inches long, this belt fits precisely and runs quietly without slippage. Made to Mercury's OEM standards, it's tough enough to handle marine heat, load, and vibra