951-10309 Carburetor

Key Features

• Optimized Fuel Atomization: Specifically jetted for MTD 159cc and 173cc vertical shaft engines, ensuring a consistent fuel-to-air ratio for easy starting and steady operation.
• Fixed-Jet Design: Features factory-set internal jets that eliminate the need for complex manual adjustments, providing "out-of-the-box" performance for walk-behind mowers.
• Corrosion-Resistant Components: Equipped with a fuel bowl and internal needle valves treated to resist the corrosive properties of ethanol-blended fuels (up to E10).
• Integrated Choke Lever: Features a durable manual choke mechanism designed for smooth movement and reliable engagement during cold starts.
• Vacuum-Tight Gasket Seal: Includes precision-cut mounting gaskets to ensure a perfect vacuum seal against the engine block, preventing RPM surging and air leaks.

Replaces / Cross-Reference Part Numbers

• 951-10309
• 751-10309
• 951-10873
• 751-10873
• 951-12098 / 751-12098 (Select models)

Compatibility & Fitment

This carburetor is a primary replacement for MTD-manufactured engines used on various push and self-propelled mowers. Key compatible brands and models include:

• MTD / Yard Machines: Fits 159cc and 173cc engine models including 5P65M0, 5P65M0A, 5P65M0B, 5P65M0C, and 5P65MU.
• Cub Cadet: Fits walk-behind mowers 11A-18JY710, CC500, and CC501.
• Yard Man: Fits push mower models 11A-41M9001 and 12A-A1M9001.
• Craftsman: Compatible with select 247-series mowers utilizing the MTD 5P65 engine platform.

When to Replace

• No-Start Condition: The engine has spark and compression but will not fire, even after cleaning the spark plug, indicating a complete fuel blockage.
• Surging or "Hunting": The engine speed cycles up and down rhythmically at idle, often caused by a restricted pilot jet or an air leak.
• Leaking Fuel: Gasoline is dripping from the bottom of the fuel bowl or from the intake, indicating a stuck float or a failed needle valve seal.
• Poor Performance Under Load: The engine dies or loses significant power as soon as it enters tall grass, suggesting the main high-speed jet is partially clogged.
• Choke Malfunction: The manual choke lever is stuck, bent, or broken, making it impossible to start the engine when cold.

Installation Tips

• Photo Reference: Before removing the old unit, take a clear photo of the throttle linkage and governor spring positions to ensure they are reinstalled correctly.
• Drain the Tank: Always drain the old gasoline from the fuel tank and line before installing the new carburetor. Using old, "stale" gas will immediately clog the new jets.
• Linkage Handling: Be careful not to stretch or bend the thin metal governor rods. They should "drop" into the plastic holes on the carburetor arm without force.
• Gasket Orientation: Ensure the paper gaskets are installed in the correct order and direction. If the gasket blocks the small pulse hole on the intake flange, the engine will not run.
• Filter Check: It is highly recommended to replace your air filter and fuel line at the same time. A dirty air filter will cause the new carburetor to run too "rich," leading to black smoke and fouled plugs.