lawn mower diagnostic
Lawn mower starts then dies
A guided diagnosis for a mower that fires up and then stalls shortly after.
Diagnostic progress20%
lawn mower
Does the mower start, run briefly, and then stall?
This diagnostic is for a mower that fires normally but will not keep running.
Before you begin
Shut the equipment down before inspecting it. Never bypass a safety switch, touch energized generator outlets, or inspect a moving blade, chain, auger, or pump.
Common questions
Why does my lawn mower start and then die after a few seconds?
The usual causes are stale fuel, a blocked fuel-cap vent, restricted fuel flow, or a clogged carburetor main jet.
Why does the mower die only when it gets hot?
A heat-related stall that clears after cooling often points to a weakening ignition coil or a valve-clearance issue rather than stale fuel.
Should I bypass the mower safety switch to test it?
No. A mower that stalls because of the operator-presence or seat safety system needs the switch or wiring repaired, not bypassed.