951-14423 Carburetor Fits for Troy Bilt MTD TB105 TB115 TB120 TB210 TB220 TB270 TB270ES ST100 SC300HW SC100 SC100HW SC500Z SC500 SC500HW SC500EZ Lawn Mower LE100 RM120 5X65RU 159CC Engines

What It Is

This is a replacement carburetor for Troy-Bilt and MTD push mowers with 159cc engines, part number 951-14423. It’s designed to replace a clogged or failed carburetor that’s causing hard starting, rough idling, or stalling.

Fitment & Compatibility

Check your engine model, not just the mower brand. This carburetor fits Troy-Bilt TB105–TB270ES and MTD SC100–SC500EZ series mowers, plus models like LE100, RM120, and 5X65RU—all with 159cc engines. It will not work on 140cc, 190cc, or larger engines.

Verify your OEM part number. This is a direct replacement for Troy-Bilt/MTD part 951-14423. Pull your old carburetor and compare the mounting pattern (two bolts, center-to-center) and fuel inlet orientation. Measure the mounting flange width—it should be roughly 2.5 inches across.

Aftermarket vs. OEM. This is an aftermarket part, not genuine MTD. It’s usually fine for most users but may need minor adjustment (see below). If you want a perfect factory fit, buy OEM.

Key Things to Know

• Expect to adjust the idle mixture screw. Most aftermarket carbs come with a pre-set screw that’s too lean. Turn it out 1.5–2 turns from fully seated after installation.
• Installation is moderate difficulty. You’ll need to remove the air filter housing, fuel line, and throttle linkage. Take photos before disassembly to aid reconnection.
• May need a new gasket. The carb may come with a gasket, but it’s often thin. Buy a separate gasket kit (PN 951-14423G) for a better seal.
• Check fuel quality first. If your old carb failed due to stale gas or debris, clean the fuel tank and line, and add a fuel stabilizer to prevent repeat failure.

Should You Buy It

Buy this if you have a 159cc Troy-Bilt or MTD mower with a dead carb and you’re comfortable with basic engine work (fuel line and throttle linkage). It’s a cost-effective fix for a common failure. Skip it if you want exact OEM fitment or if your mower has a different engine displacement—then order the correct OEM part instead.