Sierra 18-7837 Fuel Pump Diaphragm for Yamaha Outboard Motors, Type 677, Replaces Yamaha 677-24411-02-00

The Sierra 18-7837 Fuel Pump Diaphragm is a replacement diaphragm for Yamaha outboard fuel pumps, built to meet or exceed the quality of the original equipment part it replaces. The diaphragm is the flexing rubber component inside the fuel pump body that draws fuel from the tank and pushes it toward the carburetor as the pump's actuating arm cycles; when it cracks, stretches, or loses its seal, the outboard can suffer from hard starting, poor fuel delivery, or a fuel leak at the pump housing. This diaphragm is made of rubber and is sized at 0.25 x 4 x 6.5 inches to fit into the pump housing correctly.

Sierra part 18-7837 is the correct diaphragm for Yamaha outboards using engine type 677 with serial numbers ML-677-316416 and up. Confirming the type code and serial number on the powerhead before ordering ensures the correct diaphragm is installed, since fuel pump diaphragms are fit-specific across Yamaha engine type codes and serial breaks.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7837
• Product Type: Fuel Pump Diaphragm
• Material: Rubber
• Item Dimensions: 0.25 x 4 x 6.5 inches
• Weight: 0.01 pounds
• Mounting Type: Tank Mount
• Inlet Connection Type: Hose Barb
• Fitment: Yamaha outboard engine type 677, serial ML-677-316416 and up
• OEM Cross Reference: Mercury 84262M, Yamaha 677-24411-02-00, Yamaha 677-24411-01-00
• UPC: 030999323118

Fitment

• Yamaha outboard motors, engine type 677, serial number ML-677-316416 and up

Replaces (OEM)

• Mercury 84262M
• Yamaha 677-24411-02-00
• Yamaha 677-24411-01-00

Frequently Asked Questions

What does the Sierra 18-7837 diaphragm fit? The Sierra 18-7837 is built for Yamaha outboard motors with engine type 677 and serial numbers ML-677-316416 and up. Check the powerhead's type code and serial number before ordering to confirm this is the correct diaphragm.

Is the 18-7837 diaphragm interchangeable with OEM Yamaha or Mercury numbers? Yes, Sierra 18-7837 is a direct cross-reference for Yamaha 677-24411-02-00, Yamaha 677-24411-01-00, and Mercury 84262M.

What material is the Sierra 18-7837 diaphragm made of? It is made of rubber, the flexible material needed to seal and pump fuel as the pump arm actuates inside the fuel pump housing.

What are the dimensions of the 18-7837 diaphragm? The Sierra 18-7837 measures 0.25 x 4 x 6.5 inches.

How much does the Sierra 18-7837 diaphragm weigh? The Sierra 18-7837 fuel pump diaphragm weighs 0.01 pounds.

Will this diaphragm fit any Yamaha outboard fuel pump? No. The Sierra 18-7837 is fit-specific to Yamaha engine type 677 with serial numbers ML-677-316416 and up; other type codes and serial ranges use different Sierra diaphragm part numbers.

How is the 18-7837 diaphragm installed? It installs inside the fuel pump housing in place of the worn factory diaphragm, seating against the pump body so the pump arm can flex it to draw and push fuel.

Is Sierra 18-7837 a genuine Yamaha part or an aftermarket replacement? It is an aftermarket replacement diaphragm manufactured by Sierra to meet or exceed the quality of the original Yamaha equipment it replaces, sold under Sierra's own part number 18-7837.

What symptoms indicate the fuel pump diaphragm needs replacing? A worn or cracked diaphragm like the one the Sierra 18-7837 replaces typically causes hard starting, weak fuel delivery, or a fuel leak at the pump housing on affected Yamaha outboards.

What is included when I order the Sierra 18-7837? The order includes one Sierra 18-7837 fuel pump diaphragm.

How do I confirm 18-7837 is the right diaphragm for my Yamaha before ordering? Check the engine type code stamped on the powerhead and its serial number; Sierra 18-7837 applies specifically to type 677 with serial ML-677-316416 and up.