Mercury Marine

Diagphragm Kit 55278A5

Satisfaction Rating

(25 ratings)

Genuine OEM product

Product	Price	Rating	Comment
Mercury Marine 55278A5 Diagphragm Kit (viewing this product) Genuine OEM product	$8.55 ~~$10.69~~ In stock Only 5 remaining	Best	OEM Mercury kit; packaging indicates U.S. origin and the gaskets appear to be cut from Interface Performance Materials sheet (common OEM gasket stock). Best option for assured fit and long-term sealing on the fuel pump.
OEM Mercury kit; packaging indicates U.S. origin and the gaskets appear to be cut from Interface Performance Materials sheet (common OEM gasket stock). Best option for assured fit and long-term sealing on the fuel pump.
GLM Marine 40330 Fuel Pump Diaphragm Kit - GLM Products (40330) Aftermarket product	$5.39 ~~$6.74~~ In stock Only 2 remaining	Best	Very close match to the OEM pieces, using Interface Performance Materials gasket sheet and small ring gaskets with markings that resemble the OEM parts. Overall it looks like an OEM-equivalent rebuild kit with no obvious material shortcuts.
Very close match to the OEM pieces, using Interface Performance Materials gasket sheet and small ring gaskets with markings that resemble the OEM parts. Overall it looks like an OEM-equivalent rebuild kit with no obvious material shortcuts.
EMP 1300-00111 FUEL PUMP REPAIR KIT Aftermarket product	$5.94 ~~$6.99~~ In stock 5+ in stock	Better	U.S.-made kit with a well-finished diaphragm and the full gasket/O-ring set, closely matching the OEM layout. Gaskets appear to use similar Interface material (marked N-8092), but the material/marking differences suggest it may not be identical to the OEM kit.
U.S.-made kit with a well-finished diaphragm and the full gasket/O-ring set, closely matching the OEM layout. Gaskets appear to use similar Interface material (marked N-8092), but the material/marking differences suggest it may not be identical to the OEM kit.

$8.55~~$10.69~~

You save $2.14

-20%

In stock

Only 5 remaining

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This is an OEM part manufactured by Mercury Marine

30 day return policy

Product Description

Mercury factory part. Search for more factory parts & parts diagrams.

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Product Questions ⁰

Don't hesitate to ask a question. It will be answered by our support staff or a fellow boater.

25 Product Reviews

Delivery took way too long

Eric Smyth — Oct 21, 2025

CAL BURTON — Jul 30, 2025

My order was received and will order more parts from Crowley in the future!

Donald H Heyne Jr — Jun 24, 2025

Very quick shipping and fair price!

Kevin Sorge — Feb 17, 2025

Parts Fitment

Please verify fitment before ordering.

Brand	Product Line	Model
Mariner	Outboard	75
Mariner	Outboard	80
Mariner	Outboard	85
Mercury Marine	Outboard	75
Mercury Marine	Outboard	80
Mercury Marine	Outboard	85
Mercury Marine	Outboard	800
Mercury Marine	Outboard	850

Supersession Chain

Name	SKU	Superseding SKU
Diaphragm	55278A2	Current
Diagphragm Kit(viewing)	55278A5	Current

Aftermarket Interchange

Name	SKU	Price	Brand
FUEL PUMP REPAIR KIT	1300-00111	$5.01
Fuel Pump Diaphragm Kit - GLM Products (40330)	40330	$5.39

Due to manufacturer policy OEM Mercury products can only be shipped to addresses within the United States.

Flat $9.95 Shipping on ALL parts orders

Diagphragm Kit 55278A5

Product Description

Discounted Products

Product Questions 0

25 Product Reviews

Parts Fitment

Supersession Chain

Aftermarket Interchange

Product Questions ⁰