Symptoms Index 

Small Engine Symptoms Index

Use this index to quickly locate the symptom that matches what your small engine is doing — or not doing.
Each symptom below links to the most relevant category so you can read the explanation and common causes.

Won’t Start

Symptoms where the engine won’t start, won’t catch, or starts briefly and stops. See the full explanation here:
Won’t Start category.

Runs Rough

Symptoms where the engine runs unevenly, surges, coughs, or stalls. See:
Runs Rough category.

Smoke & Smells

Smoke color and unusual odors can signal different conditions and urgency. See:
Smoke & Smells category.

Power Loss

Symptoms where the engine bogs, hesitates, or won’t maintain RPM under load. See:
Power Loss category.

Fuel System Symptoms

Symptoms related to fuel delivery, flooding, leaks, or stale fuel patterns. See:
Fuel System Symptoms category.

Starting & Charging

Symptoms tied to battery, starter, and cranking behavior. See:
Starting & Charging category.

Vibration & Noise

Symptoms involving vibration, knocking, grinding, or squealing. See:
Vibration & Noise category.

Leaks & Fluids

Symptoms involving oil/fuel leaks, spots under equipment, or oil in the air filter. See:
Leaks & Fluids category.

Blades, Belts & Moving Parts

Symptoms where moving parts don’t engage, slip, squeal, or make noise. See:
Blades, Belts & Moving Parts category.

Other Engine Symptoms

Less common or mixed symptoms that don’t fit neatly into one category. Start here:
Start Here
or browse
FAQ.

Safety first: If you notice heavy smoke, fuel leaks, burning smells, sudden power loss, or loud mechanical noises,
stop using the equipment immediately and consult a qualified technician.

Last updated: March 2026

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