951-12705 / 951-10974A Snow Blower Carburetor Assembly

Key Features

• Engineered for 179cc & 208cc OHV Engines: Specifically calibrated to provide the high-torque fuel delivery required for mid-sized MTD-manufactured engines, ensuring the power needed to clear heavy, wet snow.
• Winter-Ready Cold Start Design: Features optimized internal passages and a reinforced primer bulb interface, allowing for faster fuel delivery to the combustion chamber during sub-zero starts.
• Ethanol-Resistant Internal Components: Manufactured with high-grade gaskets and a corrosion-resistant needle valve designed to withstand the degrading effects of modern ethanol-blended fuels.
• Stable Idle & Load Management: Precision-machined jets prevent the "hunting" or surging common in snow blower engines, providing a smooth transition from idling to full-throttle auger engagement.

Replaces / Cross-Reference Part Numbers

• Primary Part: 951-12705.
• Industry Standards: 951-10974, 951-10974A.
• MTD / Troy-Bilt / Cub Cadet: 751-12705, 751-10974, 751-10974A.
• Other Codes: B01MOCKKPE, PD00054321, 520-862 (Stens).

Compatibility & Fitment

This carburetor is the standard replacement for various 21-inch to 26-inch snow blowers and snow throwers. Key compatible models include:

• Troy-Bilt Storm Series: Fits Storm 2410, Storm 2620, and models 31AS62N2711, 31AS2P5C711.
• Troy-Bilt Squall Series: Direct fit for Squall 2100 and 21" single-stage units.
• Cub Cadet: Compatible with 524SWE and 2X series 179cc/208cc snow blowers.
• MTD / Yard Machines / Craftsman: Fits models 31AM62EE700, 31AS62EE731, and various 179cc/208cc 24" walk-behind units.
• Note: This carburetor is designed for engines with a **remote primer bulb** and a **manual choke**. Always verify the linkage style on your original unit before installation.

When to Replace

• Hard Starting or No Start: The most common issue caused by fuel "varnish" clogging the main jet or the internal pilot passages after the off-season.
• Engine Surging (Hunting): The engine fluctuates up and down in RPM while running, which indicates a lean fuel mixture caused by partial internal blockages.
• Leaking Fuel: A stuck float or a degraded needle seat is causing gasoline to drip from the air intake or into the engine oil.
• Runs Only on Choke: The engine dies as soon as the choke is turned off, signaling that the carburetor cannot pull enough fuel through the main circuit.
• Poor Performance Under Load: The engine bogs down or stalls as soon as you engage the auger to throw snow.

Installation Tips

• Safety First: Work in a well-ventilated area. Drain the fuel tank completely and disconnect the spark plug wire before beginning the replacement.
• Linkage Mapping: **PRO TIP:** Take a clear photo of the Z-bend governor rod and the tiny throttle return spring before removing the old carb. If these are installed in the wrong holes, the engine may over-rev and cause damage.
• Check the Primer Line: Inspect the rubber primer hose for cracks. If air leaks into this line, the primer bulb won't work, making the engine nearly impossible to start in the cold.
• Gasket Alignment: Ensure the gaskets are seated correctly and the mounting nuts are tightened evenly. An air leak at the intake flange is the #1 cause of engine surging after a carb swap.
• Fuel Management: Always use fresh, stabilized fuel (87 octane or higher). For the best results, use ethanol-free gasoline and run the carburetor dry before storing the snow blower for the summer.