Mercury Quicksilver NEW OEM Carburetor Diaphragm Kit 21-857005A1 30-65HP 0810

Mercury / Quicksilver OEM Carburetor Diaphragm Kit — Part Number 21-857005A1
Brand: Mercury / Quicksilver | Condition: New Old Stock (NOS)

You are purchasing a genuine Mercury Quicksilver OEM Carburetor Diaphragm Kit, part number 21-857005A1. This kit restores smooth, reliable fuel delivery to your carburetor's fuel system. This is an authentic factory original part — never installed, never used.

Condition Details:

This is a New Old Stock (NOS) part. The diaphragm kit itself is in new, uninstalled condition. As is common with NOS inventory, the original packaging may show signs of age, including shelf wear, dust, or minor cosmetic blemishes on the bag or box. The part is new and fully functional.

Part Number / Supersede Information:

Primary OEM Part Number: 21-857005A1
Supersedes / Replaces: 21-42990A7, 21-42990A8, 21-42990A9, 21-42990A10, 21-42990A11
Aftermarket Cross-Reference: Sierra 18-7817 | Red Rhino FM-803

21-857005A1 is the current updated OEM part number and directly supersedes all earlier diaphragm kit versions listed above. If you have been searching under any of those numbers, this is the correct current replacement.

Fitment:

• Fits: Mercury / Mariner 30HP, 35HP, 40HP, 45HP, 50HP, 55HP, 60HP, and 65HP 2-stroke outboards
• Also fits: Force outboard engines in compatible HP range
• Please verify fitment using your motor's model and serial number before ordering, as carburetor type can vary within the same HP range

Why Choose OEM Parts?

OEM parts are engineered and manufactured to exact factory tolerances, ensuring a precise fit, reliable performance, and long service life. Unlike aftermarket alternatives, OEM parts are designed specifically for your Mercury outboard motor — no modifications, no guesswork.

Returns:

We proudly offer hassle-free returns. If you are not completely satisfied with your purchase for any reason, simply open a return request through eBay within 30 days of purchase and we will take care of you promptly.

Thank you for choosing QBS Parts Inc! We truly appreciate your business. If you have any issues whatsoever with your order, please give us the opportunity to resolve it before leaving feedback — we are committed to making every transaction a great experience. Please verify fitment using your motor's model and serial number before purchasing. Feel free to message us with any questions — we're here to help!

QBS Parts, Inc. — Gardena, CA