Sierra Carburetor Kit 18-7021 for WM and WMK Mercury Outboard Carburetors

The Sierra 18-7021 Carburetor Kit is a rebuild kit engineered for WM and WMK series carburetors, including the WMK-2, WMK-3, WMK-4, WMK-5, WMK-7, and WMK-8 models. It is designed to restore carburetor performance on applicable Mercury outboard engines by replacing the wear-prone internal components that govern fuel metering and air-fuel mixture control. Components in the kit are precision-built, and Sierra recommends following the carburetor manufacturer's specifications and guidelines during installation to ensure a proper fit and correct operation after the rebuild.

This kit is intended for technicians and boat owners performing routine carburetor maintenance or troubleshooting rough idle, flooding, or poor fuel metering caused by worn internal carburetor parts. Every Sierra part, including this kit, is backed by Sierra's industry-leading customer satisfaction warranty, giving buyers confidence in fit and durability when servicing WM and WMK carburetors.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7021
• Category: Mercury Outboard Carburetors & Kits
• Compatible Carburetors: WM, WMK Carburetors (WMK-2, WMK-3, WMK-4, WMK-5, WMK-7, WMK-8)
• Exterior Finish: Machined
• Product Dimensions: 0.75 x 6 x 6 inches
• Weight: 0.05 pounds
• UPC: 030999320728

Fitment

• WM Carburetors
• WMK-2 Carburetors
• WMK-3 Carburetors
• WMK-4 Carburetors
• WMK-5 Carburetors
• WMK-7 Carburetors
• WMK-8 Carburetors

Frequently Asked Questions

What carburetors does the Sierra 18-7021 kit fit? The Sierra 18-7021 Carburetor Kit fits WM and WMK series carburetors, specifically the WMK-2, WMK-3, WMK-4, WMK-5, WMK-7, and WMK-8 models.

Is the 18-7021 a complete carburetor or a rebuild kit? It is a rebuild kit, not a complete carburetor. The Sierra 18-7021 supplies the internal components needed to rebuild an existing WM or WMK carburetor.

What are the dimensions of the 18-7021 carburetor kit? The kit measures 0.75 x 6 x 6 inches and weighs 0.05 pounds.

Does the 18-7021 kit come with an OEM warranty? Yes, the Sierra 18-7021 is covered under Sierra's industry-leading customer satisfaction warranty.

How do I know if my carburetor is a WM or WMK model? Check the carburetor's stamped model identifier for a WM or WMK designation; the Sierra 18-7021 kit is built specifically for WM and WMK-2, WMK-3, WMK-4, WMK-5, WMK-7, and WMK-8 carburetors, so confirming the model number before ordering ensures correct fitment.

What finish do the components in the 18-7021 kit have? The components included in the Sierra 18-7021 Carburetor Kit have a machined exterior finish.

Will this kit fix a rough idle or flooding issue? Rebuilding a WM or WMK carburetor with the Sierra 18-7021 kit replaces worn internal components that commonly cause rough idle, flooding, or poor fuel metering, provided the carburetor body itself is not damaged.

Is Sierra 18-7021 an authentic Sierra part or aftermarket? The 18-7021 is a genuine Sierra part, manufactured under the Sierra brand for WM and WMK carburetor applications.

Do I need any special tools to install the 18-7021 kit? Sierra recommends following the carburetor manufacturer's specifications and guidelines for proper fit and installation of the 18-7021 kit; standard carburetor rebuild tools are typically used for this type of service.

What is the UPC for the Sierra 18-7021 Carburetor Kit? The UPC for the Sierra 18-7021 Carburetor Kit is 030999320728.