Aftermarket Mercury 50HP 3-Cylinder (0G590000-0T979999) (0P017000-0P017000) (1B000001 & Up) Service Kit | Sawley's Select Marine Parts

🔧 Product Description

Aftermarket major service kit for selected Mercury and Mariner 50HP inline three-cylinder carburetted two-stroke outboards using the later standard-gearcase 821354A2 water-pump system. It covers USA serial range 0G590000-0T979999, Belgium/European production from 0P017000 and later, and later USA production from 1B000001 and up where the engine retains the applicable three-cylinder standard gearbox.

The correct European/Belgium application is 0P017000 & Up. Serial number alone is not sufficient on engines near gearcase and pump-design transitions, so the existing housing, impeller and gearbox configuration should be confirmed.

⚙️ Key Features

• Configured for later 50HP inline-three carburetted two-stroke engines

• Uses the Mercury 821354A2 complete water-pump repair family

• Includes ignition, fuel, thermostat, gearcase-drain and complete pump-service components

• Separates the standard gearbox from visually similar BigFoot/large-gearcase applications

• Incorporates current and superseded Mercury component references for easier identification

📋 Kit Contents

• 3 × NGK BP8H-N-10 spark plugs - Mercury/Quicksilver 33-97182 reference family; BPZ8H-N-10 may be used only where the engine specification calls for an RFI-suppressed equivalent

• 1 × Inline fuel filter - replaces Mercury 35-877565T / 35-877565T1

• 1 × 110°F / approximately 43°C thermostat - Mercury 850055001

• 1 × Thermostat gasket - Mercury 27-827284

• 2 × Gearcase drain/fill screw sealing washers - Mercury 12-191833 family

• 1 × Complete water-pump repair kit - Mercury 821354A2

Water-pump kit 821354A2 component breakdown:

• 1 × Impeller - Mercury 47-85089-10; related/superseded references 47-85089-3 and 8M0027792

• 1 × Drive key - Mercury 28-85119

• 1 × Wear plate - Mercury 821354-2

• 1 × Upper pump gasket - Mercury 27-822189

• 1 × Lower pump gasket - Mercury 27-822217

• 1 × Short water-tube seal - Mercury 43023 / 85180

• 1 × Long water-tube seal - Mercury 823547-1 / 85181

• 2 × Pump washers - Mercury 12-86645-1

Some aftermarket versions of the 821354A2-equivalent pump kit omit the drive key or consolidate individual seals under updated numbers. The supplied package should be checked against the component list before dismantling the gearcase.

🔄 Supersession & Cross Reference

OEM / Related References:

• Mercury 821354A2 - Complete water-pump repair kit

• Mercury 821354A1 / 821354A04 - Earlier or alternate catalogue references

• Mercury 47-85089-10 / 47-85089-3 / 8M0027792 - Impeller references

• Mercury 850055001 - Thermostat

• Mercury 35-877565T / 35-877565T1 - Fuel filter

Verified Aftermarket / Other-Brand Equivalents:

• Sierra 18-4531 - Complete water-pump repair kit equivalent

• GLM 12045 - Water-pump repair kit equivalent; some GLM packages are catalogued without the impeller key

• Sierra 18-3057 - Impeller-only equivalent

• GLM 89640 - Impeller-only equivalent

• Mallory 9-45303 - Impeller-only equivalent

• EMP 75-75011 - 110°F thermostat equivalent for Mercury 850055001

🚤 Compatibility

Commonly used on selected:

• Mercury 50HP inline three-cylinder carburetted two-stroke outboards

• Mariner 50HP versions sharing the Mercury-built three-cylinder powerhead and standard gearbox

Serial Ranges:

• USA: 0G590000-0T979999

• Belgium/European production: 0P017000 & Up

• Later USA production: 1B000001 & Up

Engine / Gearcase Identification:

• Three-cylinder carburetted two-stroke powerhead

• Standard gearcase, commonly catalogued around the 1.83:1 family for this service configuration

• 821354A2-style pump arrangement

Important Exclusions:

• Not for 60HP BigFoot or large-gearcase engines using 47-43026Q06 / 8M0100526

• Not for earlier 0D000750-0G589999 engines using the 47-19453T small-gearcase system

• Not for EFI four-stroke, OptiMax/DFI, four-cylinder or Command Thrust models

🔌 Function

Renews the principal annual-service components responsible for ignition, fuel delivery, temperature regulation, gearcase sealing and cooling-water circulation. The complete pump kit is particularly valuable where the wear plate, tube seals or pump gaskets show deterioration rather than replacing the impeller alone.

Common signs service is due include:

• Poor starting, misfire or reduced idle quality

• Restricted fuel flow or visible contamination in the filter

• Overheating, over-cooling or thermostat sticking

• Weak tell-tale stream, damaged impeller blades or scored wear plate

• Gear oil leakage from reused drain/fill screw seals

📦 Condition

• Brand-new aftermarket service kit

• New, unused replacement components

• Component manufacturer may vary while matching the listed OEM references

• Confirm the full serial number, standard gearbox ratio and 821354A2 pump layout before fitting