[Lifetime Warranty] 594601 Carburetor Replacement - Compatible with B&S 796587 591736 796250 19HP 19.5HP Engine Craftsman Riding Lawn Mower Tractor 19HP Intek Single Cylinder OHV Motor Nikki Carb

594601 Carburetor Replacement

Key Features

• Optimized for Intek Single Cylinder: Specifically jetted for Briggs & Stratton 19HP and 19.5HP Intek OHV engines, ensuring smooth power delivery and stable RPMs under heavy mowing loads.
• Anti-Afterburn Solenoid: Includes a high-response 12V fuel shut-off solenoid to prevent "backfiring" and "after-run" when turning off the engine.
• Precision Nikki-Style Casting: Manufactured with high-density alloy to match the original Nikki carburetor specifications, providing a perfect fit for the intake manifold and air filter housing.
• Corrosion-Resistant Internals: Features updated needle valves and gaskets designed to withstand the corrosive effects of ethanol-blended fuels commonly found at gas stations.
• Enhanced Fuel Atomization: Improved internal venturi design ensures better fuel-to-air mixing, leading to easier cold starts and improved fuel efficiency during long mowing sessions.

Replaces / Cross-Reference Part Numbers

• 594601
• 796587
• 591736
• 796250
• 794653
• 591910

Compatibility & Fitment

This carburetor is a direct replacement for many Craftsman riding mowers and lawn tractors equipped with Briggs & Stratton Intek engines:

• Engine Series: Primarily fits 19HP and 19.5HP Single Cylinder OHV Intek engines (e.g., 31 series engines).
• Equipment Brands: Commonly used on Craftsman, Poulan Pro, Husqvarna, Murray, and Ariens riding lawn mowers.
• Carburetor Type: Replacement for original Nikki brand carburetors with a solenoid-equipped fuel bowl.

When to Replace

• Hard Starting: The engine requires multiple tries or starting fluid to fire, indicating the internal passages are clogged with old fuel varnish.
• Engine Surging: The motor speed fluctuates up and down while at full throttle, often caused by a lean fuel mixture due to a restricted main jet.
• Fuel in Oil: If you notice the oil smells like gasoline or the oil level is rising, the internal float or needle valve has failed, allowing fuel to leak into the crankcase.
• The "No Start" Solenoid Click: If you hear a click but the mower won't start, or if you don't hear a click when turning the key, the fuel shut-off solenoid on the old carburetor may be dead.
• Leaking Fuel: Visible gasoline dripping from the carburetor body or air filter box, posing a significant fire hazard.

Installation Tips

• Clean the Fuel System: Before installing the new carburetor, drain the old gas from the tank and replace the fuel line and fuel filter. Installing a new carb with dirty gas will ruin it instantly.
• Solenoid Connection: Ensure the 12V lead to the fuel solenoid is clean and tight. If the solenoid doesn't receive power when the key is on, it will block fuel and the engine won't start.
• Gasket Alignment: Carefully inspect the mounting gaskets. If they are installed backward or misaligned, they will block the vacuum port, causing the engine to "hunt" or die under load.
• Linkage Handling: Use caution when connecting the throttle and governor linkages. Do not bend the thin metal rods, as this will result in incorrect engine speeds and potentially dangerous over-revving.
• Oil Change Recommended: If your old carburetor was leaking fuel, check your engine oil. If it smells like gas, you must change the oil and filter before running the engine with the new carburetor to prevent engine damage.