Carburetor Replacement for Briggs Stratton 594601 796587 796250 795486 591736 794136 33M977 31Q677 331777 331707 331877 Engine Lawn Mower Tractor

What It Is

This is an aftermarket carburetor replacement for many Briggs & Stratton single-cylinder engines used in push mowers, riding tractors, and zero-turn mowers. It controls the air-fuel mix entering the cylinder; when clogged or worn, it causes hard starting, stalling, or rough running.

Fitment & Compatibility

Check your engine model number (stamped on the valve cover or blower housing—starts with a number like 33M977 or 31Q677). This carburetor fits the models listed in the title: 594601, 796587, 796250, 795486, 591736, 794136, 33M977, 31Q677, 331777, 331707, 331877. It is not universal—verify your exact engine number before ordering.

Measure the mounting stud spacing (center-to-center, typically about 2.5 inches) and the bowl diameter (roughly 2 inches). Confirm your throttle/governor linkage style matches the carb’s arm configuration—some older tractors use a different lever shape. This is an aftermarket part, so gaskets and sometimes a plastic intake adapter may be needed (included in most kits).

Key Things to Know

• Quality is decent for the price – Most users report it works fine out of the box, but a few note the gaskets can be thin or the float level slightly off.
• Installation is moderate – You’ll need basic wrenching skills, a small flathead screwdriver, and patience to set the linkage. Watch a video for your specific engine model.
• Common gotcha – The new carb may need a quick cleaning (blow out ports with compressed air) and a fuel line primer bulb check; old fuel lines can crack during removal.
• Not a perfect OEM match – Some users report a bit of hesitation at full throttle or a slightly different idle mixture; tune the air/fuel screw (usually 1.5 turns out) if needed.

Should You Buy It

If your Briggs engine is hard-starting or dying under load and you’ve confirmed the engine model number matches, this carb is a solid budget fix. It’s ideal for DIYers who want to avoid a $50+ OEM part and don’t mind a little tuning. Skip it if you need exact OEM fitment or are not comfortable adjusting the idle mixture.