A pressure washer that sat all winter is the classic no-start. Most of the time it comes down to stale fuel, a fouled plug, or a safety feature doing its job. Here are six checks for gas-powered units, in the order worth trying.
1. Replace Old Fuel
Gasoline that sat for a month or more can gum up the carburetor and stop the engine from firing. Drain the tank, refill with fresh fuel, and use a fuel stabilizer if the unit will sit between uses. Make sure the fuel valve is open and the vent on the tank cap is not clogged.
2. Check the Oil Level
Most small engines have a low-oil shutoff that prevents starting when the oil is below the safe level. Check the dipstick on level ground and top off with the oil type listed in the manual.
3. Set the Choke and Primer Correctly
Cold engines usually need the choke closed and a few presses of the primer bulb if equipped. As the engine warms up, open the choke gradually. Over-priming can flood the engine, so if it smells strongly of fuel and will not catch, wait a few minutes with the choke open and try again.
4. Inspect the Spark Plug
Pull the plug and look at it. Black, wet, or oily residue means fouling. Clean it with a wire brush or replace it, and confirm the gap matches the manual. A new plug is one of the cheapest fixes on this list.
5. Clean or Replace the Air Filter
A dirty filter restricts airflow and can keep the engine from starting or cause it to run rough and stall. Check it against a light and replace it if you cannot see through it.
6. Relieve Pressure and Check the Water Supply
Many pressure washers are hard to start when there is trapped pressure in the pump. Connect the garden hose, turn the water on fully, and squeeze the trigger to release pressure before pulling the cord. Also confirm the hose is not kinked and the inlet screen is clear, since running the pump dry can damage it.
When to Call a Pro
If fuel, oil, spark, and air are all good and the engine still will not start, the carburetor may need a full cleaning or rebuild, or the recoil starter or ignition coil may have failed. A small-engine repair shop can diagnose those quickly.
Have questions about home equipment or maker-gear troubleshooting? Reach us at [email protected] or call (270) 900-6788.
FAQ
Why does my pressure washer start then die?
Usually a fuel problem such as stale gas, a partly clogged carburetor, or a clogged fuel cap vent. A dirty air filter or the low-oil shutoff can also cause stalling.
How long can gas sit in a pressure washer?
Untreated gasoline can start to degrade in about a month. Use fuel stabilizer for storage, or run the carburetor dry before putting the unit away.
Should I pull the cord with the water off?
No. Connect the water and turn it on before starting. Running the pump without water can damage the seals.
Do electric pressure washers have the same problems?
Not these ones. Electric units have no fuel, choke, or spark plug. Check the power source, GFCI outlet, extension cord rating, and that the water supply is on.