Mercury - Quicksilver Engine Starter Gear Reduction Series 12-Volt 8M6007403. Overview. There's a certain calm that settles in when you turn the key and your engine comes to life without hesitation. If you've spent enough time around the docks-or miles offshore where the water stretches quiet and wide-you know how valuable that peace of mind is. The Quicksilver 8M6007403 starter delivers that steady confidence every time. Built for select Volvo Penta engines, it gives you the kind of reliability