100% New Fuel Injector for Mercury Mariner and Tohatsu 25–30 HP 4-Stroke EFI Outboards – Replaces 8M0091784, 898101T74, 3AC-10300-1 and 3AC-10300-0
100% New Fuel Injector for Mercury Mariner and Tohatsu 25–30 HP 4-Stroke EFI Outboards – Replaces 8M0091784, 898101T74, 3AC-10300-1 and 3AC-10300-0 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
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100% New Fuel Injector for Mercury Mariner and Tohatsu 25–30 HP 4-S...
100% New Fuel Injector for Mercury Mariner and Tohatsu 25–30 HP 4-Stroke EFI Outboards – Replaces 8M0091784, 898101T74, 3AC-10300-1 and 3AC-10300-0 is backordered and will ship as soon as it is back in stock.
Product Details
This 100% new aftermarket fuel injector is designed for specified Mercury Mariner and Tohatsu 25–30 HP EFI 4-stroke outboard applications. It provides a direct replacement for the original fuel injector when the part number and complete engine fitment information match.
For Mercury applications, the injector replaces manufacturer part numbers 8M0091784 and 898101T74. For Tohatsu applications, it replaces 3AC-10300-1 and 3AC-10300-0.
- 100% new aftermarket fuel injector; not a used or remanufactured part.
- Sold as one individual fuel injector.
- Designed for gasoline EFI 4-stroke outboard applications listed below.
- Confirm the original part number, engine model, horsepower, stroke, and serial-number range before ordering.
Part Number Matrix
The following manufacturer references are associated with this replacement injector. Part-number matching should be used together with the engine fitment information.
| Brand | Manufacturer Part Number | Application |
|---|---|---|
| Mercury Mariner | 8M0091784 | 25 and 30 HP EFI 4-stroke applications |
| Mercury Mariner | 898101T74 | 25 and 30 HP EFI 4-stroke applications |
| Tohatsu | 3AC-10300-1 | MFS25 and MFS30 4-stroke applications |
| Tohatsu | 3AC-10300-0 | Listed manufacturer reference for the specified Tohatsu applications |
Engine & Model Compatibility
Fitment depends on the complete engine configuration. Match the brand, model, horsepower, stroke, and serial-number condition shown below before installation.
| Brand | Model / Application | Rated HP | Stroke | Years / Condition | Manufacturer Part Number |
|---|---|---|---|---|---|
| Mercury Mariner | 25 EFI 3-Cylinder | 25 | 4-Stroke | 2006–2021; up to serial number 1R154757 | 8M0091784 898101T74 |
| Mercury Mariner | 30 EFI 3-Cylinder | 30 | 4-Stroke | 2006–2021; up to serial number 1R154757 | 8M0091784 898101T74 |
| Tohatsu | MFS25A, MFS25B, MFS25C | 25 | 4-Stroke | Verify the complete model and serial-number information | 3AC-10300-1 3AC-10300-0 |
| Tohatsu | MFS30A, MFS30B, MFS30C | 30 | 4-Stroke | Verify the complete model and serial-number information | 3AC-10300-1 3AC-10300-0 |
Technical Specs
- Product Type
- Electronic fuel injector
- Condition
- 100% new aftermarket replacement
- Fuel System
- Gasoline electronic fuel injection
- Engine Type
- 4-stroke outboard engines
- Rated Applications
- Mercury Mariner and Tohatsu 25–30 HP EFI applications listed above
- Quantity
- One fuel injector
What’s in the Box
- 1 × 100% new aftermarket fuel injector
Installation Notes
- Confirm the original injector part number and complete engine fitment before beginning work.
- Allow the engine to cool, disconnect the battery, and follow the applicable service manual safety procedures.
- Relieve fuel-system pressure before disconnecting any fuel-system components.
- Disconnect the electrical connector and remove the fuel rail or retaining hardware as specified by the service manual.
- Remove the original injector and inspect the injector seat, retaining hardware, and sealing surfaces.
- Install the replacement injector with the correct seals and retaining components. Do not reuse damaged seals.
- Reinstall the fuel rail and electrical connection, tightening all fasteners to the manufacturer’s specified torque.
- Prime the fuel system and inspect carefully for leaks before starting the engine.
- After starting, check again for fuel leaks and confirm stable engine operation.
Professional installation is recommended because the procedure involves the pressurized fuel system.
Troubleshooting & FAQ
How do I confirm this injector fits my engine?
Compare the original injector’s manufacturer part number with the Part Number Matrix, then verify the brand, model, horsepower, 4-stroke configuration, year range, and serial-number condition in the compatibility table. If any of these details differ, confirm fitment with the engine manufacturer or a qualified marine technician.
Is this injector new or remanufactured?
This listing is for one 100% new aftermarket fuel injector. It is not a used or remanufactured component.
How many injectors are included?
One individual fuel injector is included. If your engine requires multiple injectors, order the quantity needed for your application.
What are common symptoms of a failing fuel injector?
Possible symptoms include rough idle, misfire, hard starting, poor acceleration, reduced performance, or increased fuel consumption. These symptoms can also result from other fuel, ignition, or engine problems, so diagnosis is recommended before replacement.
Can I install the injector myself?
Installation is possible for an experienced technician, but it requires work on the fuel system. Follow the applicable service manual and use professional installation if you are not familiar with fuel-system service.
Is this an OEM injector?
No. This is a 100% new aftermarket replacement. The manufacturer part numbers listed above are reference numbers used to identify the applicable replacement and are not a statement that this product is manufactured by Mercury, Mariner, Nissan, or Tohatsu.
Safety & Important Information
- Verify the part number and complete engine fitment before ordering.
- Do not work on a hot or pressurized fuel system.
- Inspect all seals and connections and check carefully for leaks before operating the engine.
- This is an aftermarket replacement component, not an OEM component.
- Professional installation is recommended for safe, leak-free operation.
About Sea Sierra
- Marine Replacement Parts — We provide replacement components for maintenance and repair of marine engines.
- Clear Fitment Information — Product references and application conditions are presented to help you verify compatibility before ordering.
- Aftermarket Value — New replacement parts for practical marine service and repair needs.
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