Mercury Quicksilver 192043 Water Pump Base Gasket — 6–15 HP Outboard

Mercury Quicksilver 192043 — Water Pump Base Gasket, 6–15 HP Outboard

Overview

Mercury Quicksilver 192043 is a genuine OEM water pump base gasket for selected Mercury and Mariner small outboards in the 6–15 HP range. It seals the base of the water pump assembly to the gearcase housing, maintaining a leak-free cooling-water circuit through the lower unit. It is the current replacement for the earlier gasket 192042 and is confirmed for selected 6–15 HP 2-stroke carbureted models and selected 9.9/15 HP 4-stroke carbureted models within serial range 0G760300–1B226999.

Supersession note: If your service records or parts diagram shows 192042, use 192043 as the correct current OEM replacement.

Fitment note: Always confirm compatibility by exact engine model and serial number using the Mercury parts catalog before ordering. Mercury uses several different water pump base gaskets across the small-outboard range, and the correct gasket must match the specific pump base and gearcase assembly.

Compatible Applications

• Mercury / Mariner 6 HP outboard — 2-stroke carbureted (serial range 0G760300–1B226999, confirm by diagram)
• Mercury / Mariner 8 HP outboard — 2-stroke carbureted (serial range 0G760300–1B226999, confirm by diagram)
• Mercury / Mariner 9.9 HP outboard — 2-stroke carbureted and 4-stroke carbureted (serial range 0G760300–1B226999, confirm by diagram)
• Mercury / Mariner 10 HP outboard — 2-stroke carbureted (serial range 0G760300–1B226999, confirm by diagram)
• Mercury / Mariner 15 HP outboard — 2-stroke carbureted and 4-stroke carbureted (serial range 0G760300–1B226999, confirm by diagram)
• Always confirm by exact engine model and serial number using the Mercury water-pump assembly diagram

Service Interval

Replace this gasket at every water pump service — whenever the water pump base is removed during impeller replacement or lower-unit service. Gaskets are a one-time-use component. Reusing a previously compressed or torn base gasket is one of the most common causes of cooling leaks after a pump rebuild.

When to Replace

• At every water pump service — whenever the pump base is being removed
• Gasket is compressed, torn, hardened, or shows any damage
• Cooling-water leakage at the pump base-to-gearcase joint
• Engine running warm or overheating with a water pump service being performed
• Any time the lower unit is opened and the water pump base is disturbed

Installation Notes

• Clean the gearcase and water-pump-base mating surfaces completely before installing the new gasket — old gasket material or corrosion on either surface will prevent a proper seal
• While the pump assembly is apart, inspect the water-inlet seal, quad ring, oil seals, face plate, and impeller for wear or damage — replacing all worn components in the same visit avoids having to re-open the lower unit shortly after
• Install the gasket in the correct orientation as shown in the Mercury water-pump diagram for the specific engine model and serial range
• A complete water pump repair kit (see Water Pump Repair Kit 42089A5) replaces the impeller, housing, base gasket, and all related seals in one service — consider ordering the full kit rather than individual components
• Follow torque specifications in the Mercury service manual for the pump housing fasteners after reassembly

Technical FAQ

• What is the difference between 192043 and the earlier 192042? 192043 is the current active Mercury OEM part number that supersedes the original 192042. They seal the same pump base location — 192043 is the correct current replacement for any application that previously used 192042. If your diagram still shows 192042, order 192043.
• Can I reuse the original base gasket during impeller service? No. The base gasket compresses under the clamping load of the pump housing and will not re-seal reliably if reused. A reused gasket is one of the most common causes of cooling-water leaks after a pump service. The gasket should always be replaced whenever the pump base is removed.
• Should I order the individual gasket or the full water pump repair kit? If the impeller is also being replaced — which it should be on any scheduled water pump service — the full Water Pump Repair Kit 42089A5 is the more practical choice. The kit includes the impeller, housing, base gasket, and related seals in one package, which is more economical and thorough than ordering individual components for the same service.
• What happens if the base gasket fails? A failed water pump base gasket allows cooling water to leak internally at the pump base, which reduces the volume of water delivered to the engine. Depending on the severity, this can cause the engine to run warm, overheat, or in sustained failure, sustain heat-related damage. The gasket is a low-cost, high-importance component in the cooling circuit.
• Is this gasket compatible with both 2-stroke and 4-stroke engines in the 6–15 HP range? Yes — 192043 is listed for both 2-stroke carbureted models and selected 9.9/15 HP 4-stroke carbureted models within the specified serial range. Always confirm by exact model and serial number, as not all engines in this HP range use the same pump base assembly.

Part Numbers & Cross-References

• Current Mercury OEM: 192043 / 27-192043
• Supersedes: 192042
• Aftermarket equivalent: Sierra 18-0995

Related Products

• Mercury MerCruiser Quicksilver Water Pump Repair Kit 42089A5
• Mercury Water Pump Gasket 858524 — MerCruiser Alpha One & Outboard
• Mercury Quicksilver 19202001 Water Pump Plate Gasket — 6 / 8 / 9.9 HP Outboard
• Mercury Quicksilver Circulating Water Pump Gasket 879150138 — MerCruiser 3.0L
• Mercury MerCruiser Quicksilver 8M0187157 Gearcase Drain & Fill Screw Seal — Blue OEM Washer

Parts Desk Insights

Best Use Case: This gasket is the correct OEM replacement for any water pump base service on Mercury and Mariner 6–15 HP outboards where the diagram calls for 192043 / 27-192043. It’s most commonly needed during a routine impeller replacement — the base gasket should always be replaced at the same time as the impeller, not saved for the next service. If you’re already in the pump, do the full job and replace the gasket. For a complete pump rebuild, order the Water Pump Repair Kit 42089A5 to cover the impeller and all related components in one service.

Common Issues: The most frequent mistake is reusing the original base gasket during an impeller replacement — the compressed gasket will not re-seal properly and can cause cooling leaks even with a new impeller installed. The second common issue is not confirming the serial number before ordering — Mercury uses different pump base assemblies across the small-outboard range, and the correct gasket must match the specific pump base geometry for the engine being serviced. Use the serial-number-specific parts diagram to confirm 192043 before ordering.