Description

Mercury / MerCruiser Quicksilver Water Pump Repair Kit — 8M0135821

The Mercury Quicksilver 8M0135821 is a genuine OEM complete water pump repair kit designed for select Mercury FourStroke EFI outboard engines. It includes the main components required to rebuild the water pump and restore proper cooling system performance.

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Key Specifications

• Part Number: 8M0135821 (also listed as 98-8M0135821)

• Component Type: Water pump repair / service kit

• Application: Lower unit water pump assembly

• OEM Brand: Mercury Marine / Quicksilver

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Compatible Engines

This kit is designed for Mercury EFI FourStroke outboards, including:

• 9.9 HP EFI ProKicker (333cc)

• 10 HP EFI

• 15 HP EFI

• 20 HP EFI

• SeaPro 10–20 HP models

Typical serial number ranges include:

• 9.9 HP EFI: 1R008146 – 1R278792

• 10–20 HP EFI:0R833820 and newer

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What’s Included in the Kit

The complete repair kit typically contains the major water-pump service components:

• Water pump impeller

• Water pump housing / case

• Liner (insert cup)

• Wear plate / guide plate

• Oil seal

• Gaskets

• Drive key

• Additional sealing components

These parts allow a full rebuild of the water pump assembly inside the lower unit.

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Function in the Engine

The water pump circulates cooling water from the lower unit through the engine block to control temperature.

A healthy water pump ensures:

• Proper engine cooling

• Protection from overheating

• Consistent water flow through the cooling system

Common signs of water pump failure include:

• Weak or no tell-tale water stream

• Overheat alarms

• Reduced cooling efficiency.

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Service Tip:
Mercury generally recommends inspecting the impeller annually and replacing it every 100–200 hours or every 1–2 years, depending on usage and water conditions.

Shipping: Ships same or next day for fast Canada wide shipping.