![\"b\u1ed9](\"https:\/\/qiyanghardware.com\/wp-content\/uploads\/2026\/03\/screenshot_2026-03-16_16-39-02.png\")
<\/figure>\n\n\n\nCarburetor l\u00e0 g\u00ec?<\/h3>\n\n\n\n
The carburetor is a mechanical device that mixes air and fuel<\/strong> in precise ratios for internal combustion. Proper carburetor function is critical for engine efficiency, fuel economy, and consistent mower performance<\/strong>. In modern small engines, the carburetor is often the main factor influencing engine reliability and smooth operation<\/strong>.<\/p>\n\n\n\nKey Functions<\/h3>\n\n\n\nFuel-Air Mixture<\/h4>\n\n\n\n\n- Ensures engine receives the correct ratio of fuel and air<\/strong> for efficient combustion.<\/li>\n\n\n\n
- Too much fuel \u2192 engine flooding, black smoke, poor fuel economy.<\/li>\n\n\n\n
- Too little fuel \u2192 engine stalling, sputtering, uneven cutting performance.<\/li>\n<\/ul>\n\n\n\n
Engine Speed Regulation<\/h4>\n\n\n\n\n- Adjusts fuel delivery based on load: thick grass, slopes, or light trimming.<\/li>\n\n\n\n
- Maintains stable RPM for consistent cutting height and blade speed<\/strong>.<\/li>\n<\/ul>\n\n\n\n
Idle and Throttle Control<\/h4>\n\n\n\n\n- Controls fuel flow during idle or full-throttle.<\/li>\n\n\n\n
- Enables smooth start-ups, responsive acceleration, and steady operation<\/strong> under different mowing conditions.<\/li>\n<\/ul>\n\n\n\n
How the Carburetor of Lawn Mower Works<\/h2>\n\n\n\n
Understanding how the b\u1ed9 ch\u1ebf h\u00f2a kh\u00ed c\u1ee7a m\u00e1y c\u1eaft c\u1ecf<\/strong> works is essential for proper maintenance, troubleshooting, and maximizing engine performance. A carburetor not only mixes fuel and air but also regulates flow, maintains stability under varying loads, and impacts fuel efficiency.<\/p>\n\n\n\nStep-by-Step Process<\/h3>\n\n\n\n1. Fuel Delivery<\/h4>\n\n\n\n
The first step in carburetor operation is fuel delivery<\/strong>. Fuel flows from the tank into the float chamber<\/strong>, where a float and float valve system maintain a constant fuel level.<\/p>\n\n\n\n\n- Float Valve Mechanism:<\/strong> The float rises and falls with fuel level, opening or closing the valve to maintain a steady supply.<\/li>\n\n\n\n
- Importance:<\/strong> Proper fuel delivery prevents engine flooding<\/strong> (too much fuel) or fuel starvation<\/strong> (too little fuel).<\/li>\n\n\n\n
- M\u1eb9o chuy\u00ean nghi\u1ec7p:<\/strong> Stale fuel or debris in the float chamber is a common cause of engine starting problems. Cleaning the chamber every season can prevent this.<\/li>\n<\/ul>\n\n\n\n
Example:<\/strong> For a typical 4-stroke push mower with a 140cc engine, the float chamber usually holds around 100\u2013150 mL of fuel<\/strong>, sufficient for 30\u201345 minutes of continuous operation.<\/p>\n\n\n\n2. Air Intake<\/h4>\n\n\n\n
Air is drawn into the carburetor through the air filter<\/strong>, which removes dust, grass, and other debris. Clean air is critical for proper combustion and prevents premature engine wear.<\/p>\n\n\n\n\n- Venturi Effect:<\/strong> Once inside the carburetor, air passes through the venturi, a narrow passage where velocity increases and pressure drops. This pressure difference draws fuel into the airstream<\/strong>.<\/li>\n\n\n\n
- Air Quality Matters:<\/strong> A clogged or dirty air filter can restrict airflow, leading to a rich fuel mixture<\/strong>, black smoke, and poor engine performance.<\/li>\n<\/ul>\n\n\n\n
M\u1eb9o:<\/strong> Check air filters every 10\u201315 hours of operation or more frequently in dusty conditions. Foam filters can be washed, while paper filters often require replacement.<\/p>\n\n\n\n3. Mixing and Atomization<\/h4>\n\n\n\n
Once fuel enters the airflow through the main jet<\/strong>, it mixes with air to form a fine mist<\/strong>, optimizing combustion efficiency.<\/p>\n\n\n\n\n- Atomization:<\/strong> Fine mist allows fuel to burn more completely, producing maximum power and minimal emissions<\/strong>.<\/li>\n\n\n\n
- Fuel-Air Ratio:<\/strong> Ideal ratios for small engines are typically around 14.7:1<\/strong> (air:fuel by weight). Deviations can lead to:\n
\n- Too rich \u2192 black smoke, carbon deposits, fouled spark plugs<\/li>\n\n\n\n
- Too lean \u2192 overheating, engine knocking, stalling<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n
Note:<\/strong> Using ethanol-blended fuels can cause corrosion and gum formation in the jets if not cleaned regularly.<\/p>\n\n\n\n4. Combustion<\/h4>\n\n\n\n
The air-fuel mixture is drawn into the cylinder and ignited by the spark plug<\/strong>. This creates the power that rotates the blades and drives the mower.<\/p>\n\n\n\n\n- Power Transmission:<\/strong> The combustion pressure pushes the piston down, turning the crankshaft and transferring motion to the mower blades.<\/li>\n\n\n\n
- Efficiency Consideration:<\/strong> A well-adjusted carburetor can increase fuel efficiency by 10\u201315%<\/strong> compared to a poorly tuned one.<\/li>\n<\/ul>\n\n\n\n
M\u1eb9o:<\/strong> For mowers with high RPM engines (e.g., 3,400\u20133,600 RPM), even minor carburetor misadjustments can noticeably affect cutting performance.<\/p>\n\n\n\nCommon Problems with Lawn Mower Carburetors<\/h2>\n\n\n\n![\"b\u1ed9](\"https:\/\/qiyanghardware.com\/wp-content\/uploads\/2026\/03\/screenshot_2026-03-16_16-40-25.png\")
<\/figure>\n\n\n\nUnderstanding the common issues helps with preventive maintenance<\/strong> and quick troubleshooting.<\/p>\n\n\n\nEngine Won\u2019t Start<\/h3>\n\n\n\n\n- Nguy\u00ean nh\u00e2n:<\/strong>\n
\n- Clogged jets preventing fuel flow<\/li>\n\n\n\n
- Stale fuel causing gum and varnish buildup<\/li>\n\n\n\n
- Float valve stuck or misaligned<\/li>\n<\/ul>\n<\/li>\n\n\n\n
- Gi\u1ea3i ph\u00e1p:<\/strong>\n
\n- Clean carburetor thoroughly<\/li>\n\n\n\n
- Replace old fuel<\/li>\n\n\n\n
- Inspect and adjust the float<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n
Case Example:<\/strong> A homeowner reported that their push mower would crank but not start. Cleaning the carburetor jets and replacing fuel resolved the issue within 20 minutes.<\/p>\n\n\n\n