1. Vapor Lock: When the engine is hot, the fuel in the carburetor can vaporize and form bubbles, causing a vapor lock. This prevents fuel from reaching the engine, resulting in a hard or no-start condition.
2. Fuel System Issue: A faulty fuel pump, clogged fuel filter, or kinked fuel line can restrict fuel flow to the engine, especially when it is hot.
3. Spark Plug Problems: A worn-out or fouled spark plug can cause ignition issues when the engine is hot. Check the spark plug and replace it if necessary.
4. Electrical Issues: Faulty ignition components, such as a bad ignition coil, ignition module, or wiring issues, can affect the engine's ability to start when hot.
5. Overheating: If the engine is overheating, it may cause various problems, including starting issues. Check the coolant level, radiator, and thermostat to ensure proper cooling.
6. Compression Problems: Reduced engine compression due to worn piston rings, valves, or cylinder head issues can make starting the engine difficult, especially when hot.
7. Fuel Quality: Using old or contaminated fuel can cause engine starting problems. Ensure you are using fresh, clean fuel.
8. Mechanical Issues: More severe mechanical problems, such as a damaged crankshaft, camshaft, or timing chain, can also lead to starting issues.
If the lawnmower starts fine when cold but not when hot, it is essential to address the problem promptly to prevent further damage and inconvenience. It's recommended to troubleshoot and inspect the suspected components mentioned above. If the issue persists, it's best to consult with a qualified repair technician.
