Fuel Pump Diaphragm Kit 21-857005A1 for Mercury Mariner 30-250 HP
Fuel Pump Diaphragm Kit 21-857005A1 for Mercury Mariner 30-250 HP
Product Overview
Fuel pump diaphragm kit for Mercury Marine outboard and Sport Jet engines, supplied as 1 x diaphragm kit. It replaces 21-857005A1 and the whole 21-42990 range from A1 through A11, plus Sierra 18-7817. The kit is also used on Chrysler, Force, US Marine and Sea Ray engines running the same pump body. Fitment covers 30 to 250 HP models. Replace the diaphragm when the engine floods, loses fuel pressure at speed, or fuel is found in the pump body or the crankcase. A pinhole in the diaphragm is the usual cause of a pump that will not hold prime.
Specifications & Attributes
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Fuel Pump Diaphragm Kit |
| Engine | Mercury, Chrysler, Force, US Marine, Sea Ray |
| Horsepower | 30-250 HP |
| Quantity | 1 kit |
| Packaging Size | 15 x 18 x 1 cm (5.9 x 7.1 x 0.4 in) |
OEM Cross Reference
| Brand | OEM Part Numbers |
|---|---|
| Mercury | 21-857005A1, 21-42990A1, 21-42990A2, 21-42990A3, 21-42990A4 |
| Mercury | 21-42990A5, 21-42990A6, 21-42990A7, 21-42990A8, 21-42990A9 |
| Mercury | 21-42990A10, 21-42990A11 |
| Sierra | 18-7817 |
Compatible Engines
| Brand | Note |
|---|---|
| Mercury | Outboard 30-250 HP |
| Mercury Sport Jet | Same pump body |
| Chrysler / Force | Same pump body |
| US Marine / Sea Ray | Same pump body |
What's Included
| Component | Qty |
|---|---|
| Diaphragm Kit | 1 |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | Standard |
| Packaging | Sealed retail packaging |
Before You Buy
- Confirm the pump body on your engine matches the numbers above
- Check the pump check valves while the body is open
- Clean both mating faces before fitting the new diaphragm
- Prime the system and check for leaks before launching
- 30-Day Easy Returns
- Free Worldwide Shipping
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Before You Buy
Frequently Asked Questions
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