Why Mowers Fail to Start After Winter Storage
The culprit in 90% of cases is stale petrol in the carburettor. Modern petrol (especially E10 blends with ethanol) begins to degrade in as little as 30 days. After 4–5 months of winter storage, varnish deposits from evaporated petrol clog the carburettor's tiny jets. The engine can't draw fuel — so it won't start, or starts briefly then dies.
Step-by-Step Spring Startup
Step 1 — Drain Old Fuel
Open the fuel tap (or tilt the mower to drain) and remove all old petrol. Dispose of it responsibly. If the fuel is more than 60 days old, this step alone resolves most starting problems when combined with fresh fuel.
Step 2 — Add Fresh Petrol
Fill with fresh 95 RON unleaded. Avoid E10 — use E5 or premium if available. Add fuel stabiliser if you won't mow frequently.
Step 3 — Check Oil Level
Top up if needed. Many mowers have a low-oil kill switch — a dry engine won't start regardless of other factors.
Step 4 — Remove and Inspect Spark Plug
Remove with a spark plug socket. If the electrode is grey or light tan: it's fine. If black, sooty or damp with oil: replace it (€5–€8 at any hardware store). Gap the new plug per manual spec.
Step 5 — Try Starting
Set choke to FULL (cold start), fuel tap OPEN, throttle to FAST. Pull 3–4 times. If it fires briefly then dies, the carb is partially clogged — proceed to Step 6.
Step 6 — Clean the Carburettor
With the engine stopped, remove the air filter. Spray carburettor cleaner liberally into the air intake. Wait 2 minutes. Try starting again. For stubborn cases, remove the carburettor float bowl (usually one bolt), clean the bowl and jets with carb cleaner, and blow through the jets with compressed air.
Step 7 — Blade Inspection
Before mowing, inspect the blade for damage from any stones or debris left on the lawn over winter. A chipped or bent blade must be replaced before use.
FAQ
How can I avoid this problem next year?
Before putting the mower away in autumn: add fuel stabiliser and run for 5 minutes to treat the carburettor, then run the engine until it stops from fuel starvation. An empty carburettor can't develop varnish deposits.
