Beef Up Your Boat Fuel System With This Heavy Duty Diaphragm Kit For Mercury Quicksilver Outboard Engines Ranging 35 To 150 HP Direct Fit For 21 Series 42990A7 A8 A9 A10 And 857005A1 Sierra 18 7817 Compatible Marine Grade Replacement

Heavy Duty Diaphragm Kit for Outboard Engines 35-150 HP
✔️ Direct fit for 21-series 42990A7/A8/A9/A10 and 857005A1

This heavy-duty diaphragm kit is designed to upgrade and replace worn diaphragms in Mercury Quicksilver outboard engine fuel systems, covering 35-150 HP from 21-series parts. It's commonly used on boats with Mercury Quicksilver 21-series engines to restore reliable fuel delivery.

✅ Fit Part Numbers include 21-42990A7, 21-42990A8, 21-42990A9, 21-42990A10, 21-857005A1
✅ Engine range: 35HP-150HP
✅ Sierra 18-7817 compatible
✅ Marine-grade replacement for durable service

💡 What is a diaphragm kit for Mercury Quicksilver outboard engines used for in a boat fuel system?

Here's a handy breakdown of its purpose:

- Diaphragm-based fuel system maintenance and seal integrity
- Supports stable fuel delivery for 21-series Mercury Quicksilver outboards
- Sierra 18-7817 compatibility and marine-grade reliability