799871 Carburetor Carb Replacement for 790845 799866 796707 794304 For Lawn Boy Toro Craftsman Lawn Mower with Gaskets

What It Is

This is a complete carburetor replacement assembly for small engines (typically 140cc–190cc) used in push mowers and lawn tractors. It includes the carb body, gaskets, and often the fuel line or filter—designed to fix hard-starting, stalling, or poor-idle issues caused by clogged or worn-out carburetors.

Fitment & Compatibility

Before buying, verify these three things:

• OEM cross-reference numbers: This carb replaces part numbers 790845, 799866, 796707, and 794304. Check your mower’s manual or old carb for one of these numbers.
• Brand/model fit: Compatible with select Lawn Boy, Toro, and Craftsman mowers using a side-draft carb (typical on Briggs & Stratton or Tecumseh engines). Not for all Toro or Craftsman models—double-check engine brand and model number on the engine shroud.
• Physical measurements: Carburetor body is roughly 2.5” x 2” x 1.5”. The mounting flange uses two bolts spaced 1.5” apart center-to-center. The fuel inlet is a 90-degree barbed fitting (5/16” ID fuel line). If your mower uses a different fuel line size or vertical-mount carb, this won’t fit.

Key Things to Know

• Quality vs. OEM: This is an aftermarket part—works well for most users, but tolerances may be slightly looser than OEM. Expect to adjust the idle mixture screw (turn 1.5 turns out from seated as a baseline).
• Installation difficulty: Moderate—takes 20–45 minutes. Requires removing the air filter housing, old carb, and swapping gaskets. Have a small screwdriver, 8mm/10mm socket, and needle-nose pliers ready.
• Common gotcha: Gaskets may be slightly thicker than OEM—do not overtighten the mounting bolts or you’ll warp the carb flange. Use a crisscross pattern and snug, not crank.
• Fuel line compatibility: The included gaskets and fuel line may not match every mower. Test-fit the fuel line; if it’s too short or loose, reuse your old line or buy a 5/16” ID replacement.

Should You Buy It

If your mower is hard to start or runs rough and you’ve confirmed the carb number cross-reference, this is a solid budget fix—especially for older mowers where OEM parts cost $40+. It’s not for pros needing exact OEM fit, but for DIYers, it’s a reliable way to get your mower running again without overspending.