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Boost Pump – Fits Mercury Marine 75-300 HP Optimax/DFI/Pro XS (Replaces 888733T02)

Sale price $109.00 Regular price $174.00
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Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This aftermarket Boost Pump – Fits Mercury Marine 75-300 HP Optimax/DFI/Pro XS (Replaces 888733T02) is designed for Mercury Marine 75-300 HP 2-Stroke Optimax, DFI, Pro XS, and Racing XS outboard engines from 2003–2014. It serves as a reliable low-pressure electric fuel boost pump, ensuring consistent fuel delivery for optimal engine performance.

It is a direct replacement for Mercury/Quicksilver part numbers 888733T02 and 888733T1.

  • Installs horizontally inside the VST (Vapor Separator Tank).
  • Features a direct plug-in OEM electrical connector for simple installation.
  • Engineered with flow and current characteristics matching original equipment.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand Part Number
Mercury / Quicksilver 888733T02
Quicksilver 888733T1

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This part is designed for specific Mercury Marine outboard engines.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Mercury Optimax (1.5L) 75 2-Stroke 2005–2014 888733T02
Mercury Optimax (1.5L) 80 Jet 2-Stroke 2007–2014 888733T02
Mercury Optimax (1.5L) 90 2-Stroke 2004–2014 888733T02
Mercury Optimax (1.5L) 115 2-Stroke 2004–2014 888733T02
Mercury Pro XS (1.5L) 115 2-Stroke 2010–2015 888733T02
Mercury Optimax (1.5L) 125 2-Stroke 2008–2012 888733T02
Mercury Optimax (3.0L) 200 2-Stroke 2003–2018 888733T02
Mercury Pro XS (3.0L) 200 2-Stroke 2007–2018 888733T02
Mercury Optimax (3.0L) 225 2-Stroke 2003–2018 888733T02
Mercury Pro XS (3.0L) 225 2-Stroke 2004–2018 888733T02
Mercury Sport XS (3.0L) 225 2-Stroke Up to 2018 888733T02
Mercury Optimax (3.0L) 250 2-Stroke 2004–2014 888733T02
Mercury Pro XS (3.0L) 250 2-Stroke 2006–2018 888733T02
Mercury Sport XS (3.0L) 250 2-Stroke Up to 2018 888733T02
Mercury Optimax (3.2L) 300 2-Stroke 2015–2018 888733T02
Mercury DTS (3.0L) 225 2-Stroke 2003–2018 888733T02

Technical Specs

Product Type
Electric Low Pressure Fuel Boost Pump
Installation
Horizontal mounting in VST Tank
Fuel Type
Gasoline (Optimax Direct Fuel Injection system)
Connection
Direct plug-in (OEM electrical connector)
Housing Material
Plastic
Dimensions
16.5 × 8.5 × 7.5 in (419 × 216 × 191 mm)
Weight
0.37 kg (0.81 lb)
Warranty
1 Year (aftermarket parts)
Other Technical Attributes
Flow/Current same as OE

What’s in the Box

  • 1 x Fuel Boost Pump Assembly (888733T02)

Installation Notes

  1. Disconnect the boat's battery and relieve all fuel system pressure.
  2. Carefully access the Vapor Separator Tank (VST) assembly on the engine.
  3. Unplug the old pump's electrical connector and disconnect the fuel lines, noting their positions.
  4. Remove the old boost pump from its mounting inside the VST.
  5. Install the new pump, ensuring it is seated correctly in the horizontal orientation.
  6. Securely reconnect the fuel lines and plug in the direct-fit electrical connector.
  7. Reassemble the VST, prime the fuel system according to your engine's manual, and reconnect the battery.
  8. Before starting the engine, thoroughly check all connections for leaks.

Troubleshooting & FAQ

How do I confirm this pump fits my specific engine model?

Always check your engine's serial number and original part number. Compare it against the information in the 'Engine & Model Compatibility' and 'Part Number Matrix' tables. If your model and year are listed, and the part number matches, it is compatible.

What are the common signs of a failing fuel boost pump?

Symptoms of a failing low-pressure boost pump include difficulty starting, bogging down under acceleration, stalling at idle, or a noticeable drop in top-end engine RPMs. These issues occur because the high-pressure pump is starved of fuel.

Is this a direct plug-and-play installation?

Yes, this pump is designed to be a direct replacement. It uses the same style of electrical connector as the OEM part and fits directly into the VST housing without modification.

How does this aftermarket pump compare to the original Mercury part?

This pump is engineered to meet or exceed original equipment specifications for flow rate, pressure, and durability. It offers comparable performance and reliability to the OEM part but at a more accessible price point.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost?

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns?

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

  • Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
  • This is an aftermarket replacement, not an OEM component.
  • Professional installation is recommended for safety and performance.

About Sea Sierra

  • Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
  • Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
  • Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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