Mercury - Quicksilver Propeller Thrust Holder Fits Mercury & Mariner 8-9.9 HP FourStroke Outboards 8M0131240. Overview. There's a certain peace that comes from knowing every part of your outboard is doing exactly what it's meant to do. The Quicksilver Propeller Thrust Holder ( 8M0131240) delivers that kind of reliability. It's small, simple, but absolutely essential - a part that keeps your propeller locked in place so you can focus on what matters: smooth power, steady motion, and a boat that p