Engineered Marine Products Fuel Pump Repair Kit 1399-39020, Replaces 21-42990A7 18-7817, Mercury Mariner Square Pump Outboards

This fuel pump repair kit from Engineered Marine Products is built to restore the fuel delivery system on Mercury Mariner outboards equipped with the square-style fuel pump. Rather than replacing the entire pump assembly, this kit supplies the wear components needed to bring a tired or leaking pump back to proper working condition, saving the cost of a full pump replacement. The kit is constructed from plastic and rubber components engineered to withstand continuous exposure to fuel and the vibration and heat found in an outboard engine compartment. Included in the kit is a fuel pump with filter, giving the installer the core parts needed to complete the rebuild in one job rather than sourcing individual pieces separately. Engineered Marine Products backs this kit with a 1 year manufacturer warranty, reflecting confidence in the materials and fit. This kit is intended for Mercury Mariner outboards using the square fuel pump design across a wide horsepower range, from smaller kickers up through larger offshore-rated outboards. Boat owners and marine technicians use kits like this one when a fuel pump is showing signs of reduced fuel pressure, hard starting, or a visible fuel leak at the pump diaphragm. Because the part restores original pump function using the manufacturer's specified components, it is a straightforward, cost-effective way to keep an outboard's fuel system reliable without replacing the whole pump housing.

Specifications

• Brand: Engineered Marine Products
• Manufacturer Part Number: 1399-39020
• Category: Mercury Outboard Fuel Pump Kit
• Included Components: Fuel Pump With Filter
• Material: Plastic, Rubber
• Weight: 0.04 pounds
• UPC: 840080472386
• Manufacturer Warranty: 1 year
• OEM Cross-Reference: 21-42990A7, 18-7817
• Compatible Horsepower Range: 35, 40, 45, 50, 55, 60, 65, 75, 80, 90, 100, 115, 125, 135, 150, 175, 200, and 275 horsepower
• Compatible Pump Type: Square fuel pump
• Vehicle Type: Boat

Fitment

Fits Mercury Mariner outboards that use the square-style fuel pump, spanning 35 through 275 horsepower models.

Replaces (OEM)

21-42990A7, 18-7817

Frequently Asked Questions

What does the 1399-39020 fuel pump kit include? The 1399-39020 kit from Engineered Marine Products includes a fuel pump with filter, giving you the core components needed to rebuild the pump in one job.

Which outboards does this fuel pump kit fit? This kit fits Mercury Mariner outboards that use the square-style fuel pump, covering models from 35 up to 275 horsepower.

Does 1399-39020 replace OEM part 18-7817? Yes, part 1399-39020 is a direct replacement for OEM number 18-7817 as well as 21-42990A7.

Is this kit compatible with 21-42990A7? Yes, the Engineered Marine Products kit 1399-39020 replaces OEM number 21-42990A7.

What material is the fuel pump kit made from? The 1399-39020 fuel pump repair kit is made from plastic and rubber components designed to handle continuous fuel exposure and engine compartment heat.

How much does the fuel pump kit weigh? The 1399-39020 fuel pump repair kit weighs 0.04 pounds.

Is this a genuine or aftermarket fuel pump kit? This is an aftermarket kit manufactured by Engineered Marine Products, built to replace the OEM square fuel pump on compatible Mercury Mariner outboards.

Does the kit come with a warranty? Yes, the 1399-39020 fuel pump kit is backed by a 1 year manufacturer warranty from Engineered Marine Products.

Can I use this kit to fix a leaking fuel pump? Yes, this kit is designed for rebuilding a Mercury Mariner square fuel pump that is leaking or losing fuel pressure, using the included pump and filter components.

What horsepower engines can use the 1399-39020 kit? The 1399-39020 kit is compatible with square-pump Mercury Mariner outboards ranging from 35 to 275 horsepower.

Do I need to replace the whole fuel pump assembly or just this kit? The 1399-39020 kit lets you rebuild the existing square fuel pump on your Mercury Mariner outboard rather than purchasing an entirely new pump assembly.