753-06190 Carburetor - Fits Troy Bilt TB22, TB21EC, TB22EC, TB32EC, Murray - Replaces WT-973

753-06190 Carburetor

Key Features

• Precision Fuel-Air Mixing: Factory-calibrated to provide the optimal stoichiometric ratio for 25cc to 31cc 2-cycle engines, ensuring a stable idle and smooth transition to high RPMs.
• Enhanced Cold-Start Reliability: Features an optimized internal primer circuit and high-response needle valves to reduce the number of pulls required to start your equipment after storage.
• Ethanol-Resistant Components: Equipped with upgraded internal diaphragms and seals specifically engineered to resist the hardening and "gumming" caused by modern ethanol-blended fuels.
• High-Durability Alloy Casting: Manufactured from corrosion-resistant aluminum alloy to withstand the high-vibration and high-heat environment of handheld garden power tools.
• Complete Maintenance Kit: Designed as a direct "drop-in" replacement that typically includes the necessary gaskets and hardware to ensure a vacuum-tight seal during installation.

Replaces / Cross-Reference Part Numbers

• Walbro: WT-973, WT973, WT-973-1
• MTD / Troy-Bilt: 753-06190, 753-06190A
• Other: 753-01690, 753-06190

Compatibility & Fitment

This carburetor is the primary fuel system component for a wide range of MTD-manufactured 2-cycle handheld tools. Key compatible models include:

• Troy-Bilt Trimmers: TB21EC, TB22, TB22EC, TB32EC, TB42EC, TB80EC, TB2040XP.
• Murray Models: M2500, M2510 Brushcutters and String Trimmers.
• Bolens Models: BL110, BL160, BL425.
• Remington & Yard-Man: Various 25cc/27cc 2-cycle trimmers utilizing the WT-973 style carburetor.

When to Replace

• Engine "Bogging" Under Load: The trimmer idles fine but stalls or loses power as soon as you pull the trigger to cut thick grass, indicating a clogged high-speed jet.
• Starts Only with Fluid: The engine will only fire if starting fluid is sprayed into the intake, confirming the carburetor is no longer drawing fuel from the tank.
• Fuel Leaks: Gasoline drips from the air filter housing or the primer bulb area while the unit is off or running, which is a significant fire hazard.
• Surging Idle: The engine RPM fluctuates wildly at idle (often called "hunting"), typically caused by an air leak at the carburetor gaskets or a lean fuel mixture.
• Brittle Primer Bulb: The clear primer bulb has yellowed, cracked, or stays "sunk in" after being pressed, preventing the system from priming.

Installation Tips

• Drain the Old Fuel: Before installing the new carburetor, completely drain the gas tank and replace the fuel filter. Old, "varnished" gas will immediately clog the fine internal screens of your new unit.
• Take a Photo: Use your phone to take a clear picture of the throttle linkage and fuel line routing before you disconnect anything. This ensures you get the "Z-bend" on the throttle cable back into the correct hole.
• The Pulse Hole Rule: When placing the new gasket, ensure the tiny hole on the gasket aligns perfectly with the pulse hole on the engine block. If this is blocked, the internal fuel pump will not function.
• Hand-Tighten Only: Tighten the two mounting bolts evenly and firmly by hand. Using an impact driver can warp the carburetor flange or strip the plastic threads in the engine shroud.
• Purge the Air: Once installed, press the primer bulb 10 times until you see clear fuel (without air bubbles) returning through the return line to the tank before attempting the first start.