Symptoms
- Engine loses power and stalls after running a while
- Hot smell coming from the engine
- Engine hard to restart once hot
- Visible dirt or grass packed around cooling fins
Likely causes
- CommonDebris blocking cooling fins or shroudingGrass clippings and dust reduce airflow needed to cool the engine.
- CommonLow or old engine oilOil helps dissipate heat, and low or degraded oil increases engine temperature.
- PossibleExtended heavy-load operationContinuous hard use without rest periods can overheat small air-cooled engines.
- PossibleIncorrect fuel mixture (two-stroke engines)Too little oil in a two-stroke mix increases friction and heat.
What to do
- Let the engine cool completely before inspecting or touching any part of it.
- Clean debris from the cooling fins, shrouding, and air intake screen.
- Check the oil level and condition; top off or change if low or dirty.
- For two-stroke engines, verify the fuel-oil mix ratio matches the manufacturer's specification.
- Give the engine rest periods during heavy or extended use.
- Check that the muffler and spark arrestor aren't clogged, which can also cause overheating.
- If overheating continues after cleaning and oil checks, have the cooling system and engine inspected by a small-engine mechanic.
Tools and parts
- Soft brush
- Engine oil
Small engine oilSearch: “small engine oil SAE 30”
When to call a pro
If overheating persists after basic maintenance, a small-engine shop can check for internal cooling or lubrication issues.
Safety
Use caution
Let the engine fully cool before touching any part of it to avoid burns.