591137 Carburetor

Key Features

• Precision Fuel-to-Air Mixing: Engineered specifically for 190cc professional-grade engines to ensure smooth idling and maximum power output under heavy load.
• Corrosion-Resistant Plastic Body: Unlike older metal carburetors, this composite design is highly resistant to ethanol-related corrosion and "gumming" caused by modern fuels.
• Auto-Choke Compatibility: Designed to work seamlessly with the Briggs & Stratton ReadyStart system, allowing for easy starting without the need for manual choking or priming.
• OEM-Spec Mounting: Features precision-molded intake and air cleaner mounting holes for an airtight seal, preventing dirt ingestion and vacuum leaks.
• Pre-Set Jetting: Comes factory-calibrated for high-torque engines (7.75HP to 8.75HP), requiring zero internal adjustments for standard operation.

Replaces / Cross-Reference Part Numbers

• 591137
• 590948
• 594287
• 799248

Compatibility & Fitment

This carburetor fits a wide range of high-performance outdoor power equipment powered by Briggs & Stratton 190cc engines. Key compatible equipment includes:

• Engines: Fits 775ex, 850ex, 875ex, and 875exi series Vertical Shaft engines.
• Pressure Washers: Commonly used on Troy-Bilt, Craftsman, and Briggs & Stratton 2800–3200 PSI units.
• Lawn Mowers: Fits premium self-propelled walk-behind mowers from Troy-Bilt, Toro, and Snapper utilizing the 190cc 8.75 HP engine.
• Note: Verify that your original carburetor has the same plastic-body design, as some older 190cc engines used a metal-body carburetor that is not interchangeable.

When to Replace

• "Surging" Idle: The engine speed fluctuates up and down rapidly while running, often caused by a partially clogged internal pilot jet.
• Leaking Fuel: Gasoline is dripping from the air filter housing or the bottom of the carburetor, indicating a stuck internal float or a worn needle valve.
• Engine Won't Start: The spark plug is dry after multiple pulls, suggesting the carburetor is not delivering fuel to the combustion chamber.
• Difficulty Starting: The engine will only start if a small amount of fuel is poured into the air intake (priming the engine manually).
• Ethanol Damage: The engine has been sitting with untreated fuel for more than 90 days, leading to internal varnish and clogs that cannot be easily cleaned.

Installation Tips

• Clean First: Use a brush or compressed air to remove all dirt and debris from the engine block around the old carburetor before removal to prevent engine damage.
• Gasket Placement: Ensure the mounting surface is perfectly clean. Reuse the original plastic spacer (heat shield) between the carburetor and the engine, but always use new paper gaskets.
• Snap-Fit Linkages: The throttle and choke linkages on these plastic carburetors can be delicate. Use needle-nose pliers to gently guide the "Z-bend" rods into their respective plastic arms.
• Check the Air Filter: If your old carburetor was leaking, your air filter may be soaked in gasoline. A wet air filter will restrict airflow and cause the engine to smoke or run poorly.
• Fresh Fuel & Stabilizer: Always drain the old gas from the tank and fuel line. Use fresh 87+ octane fuel and add a fuel stabilizer to prevent the new carburetor from clogging during storage.