Common Problems Causing Small Engines to Fail Suddenly Without Warning

Introduction to Small Engine Failures

When it comes to the breakdown of small engines, two key issues often surface as the primary reasons for their sudden and unexpected failure: fuel system problems and electrical/ignition system failures. In addition to these, overheating is another common issue that ranks high in damaging small engines. Understanding these problems can help in preventative maintenance and timely troubleshooting.

Fuel System Problems

90% of small engine repairs involve fuel system issues, ranging from water in the gas, stale gas, corroded or clogged carburetors, and leaking or clogged air filters. These problems can lead to a complete breakdown of the engine without any prior warning. The fuel system is often the first to suffer in poorly maintained or neglected small engines.

Electrical and Ignition System Problems

The second most common issue is related to the electrical and ignition systems. Issues such as failed or fouled spark plugs, failed low oil shutdown systems, failed switches, and wiring problems are frequent culprits. On lawn mowers, hitting hard objects like tree stumps can lead to sheared flywheel keys and altered spark timing, causing ignition problems. Regular maintenance and inspections can help prevent these failures.

Overheating and its Effects

Overheating is the leading cause of small engine failures, particularly in air-cooled engines. Dust, sand, and grime from the environment can accumulate on cooling fins, leading to increased engine temperature and eventually, engine seizure or damage to internal components, such as valves. Air, introduced through a faulty or missing air filter, can act as sandpaper, causing internal wear and the burning of engine oil.

Real-life Example of Engine Overheating

Take, for example, a pair of old Kohler 7-horsepower generators. Running continuously in a construction environment, these generators were exposed to dust and grime. Over time, the oil level would drop, and the generator would seize up, leading to a catastrophic failure. If you’ve ever witnessed what happens to a generator in such conditions, you can appreciate the destructive impact of neglect and environmental factors.

The Role of Proper Maintenance

Regular maintenance is crucial to preventing these issues. For engines that don’t get used frequently, such as homeowner chainsaws, mowers, emergency generators, and snow blowers, the key is to drain the fuel tank and run the carburetor dry. This simple step can fix 95% of fuel system-related problems. However, not everyone takes the time to perform these basic maintenance tasks, leading to avoidable breakdowns.

Conclusion

While fuel system and electrical/ignition problems, along with overheating, are the most common causes of small engine failures, good maintenance practices can significantly reduce these incidents. Recognizing these issues early and taking timely action is essential for keeping small engines running smoothly and efficiently.