On most Simpson pressure washers, the throttle is fixed and cannot be adjusted by the user. These machines are engineered to operate at a specific engine speed, typically at "MAX" or "RUN" settings, to ensure the pump generates the high pressure needed for effective cleaning.
Understanding Your Pressure Washer's Throttle
A pressure washer's throttle controls the engine's RPM (revolutions per minute), which in turn directly affects the pump's ability to produce high water pressure. For the majority of pressure washer models, including many Simpson units, the engine is designed to run at a consistent, high speed to deliver optimal cleaning performance.
Why is the Throttle Usually Fixed?
- Optimal Performance: Running the engine at a high, constant RPM ensures the pump consistently delivers maximum pressure and flow (GPM - gallons per minute).
- Pump Efficiency: Pressure washer pumps are most efficient at their designed operating speed.
- Simplicity: A fixed throttle simplifies operation, allowing users to focus on the cleaning task rather than engine adjustments.
When an Adjustment Might Be Possible (and What It Means)
While most consumer-grade pressure washers have fixed throttles, some professional or commercial models, or those featuring specific engine types, might have a rudimentary throttle control.
If your particular Simpson pressure washer's engine does have a throttle control:
- Set it to "MAX" or "RUN": This position is crucial as it allows the pump to create the high pressure needed for most cleaning operations. Operating at lower RPMs will significantly reduce the cleaning power.
| Throttle Setting | Engine Speed (RPM) | Pressure Output | Best for |
|---|---|---|---|
| MAX / RUN | Highest | Maximum | All cleaning tasks requiring high pressure |
| Idle | Lowest | Minimal | Starting/stopping engine, brief pauses (if available) |
It is essential to consult your specific Simpson pressure washer's owner's manual for detailed instructions regarding engine operation and any available throttle controls.
How to Control Pressure if the Throttle is Fixed
Since adjusting the throttle isn't typically an option for managing pressure, you should use other methods to adapt your Simpson pressure washer to various cleaning tasks.
Here are the most effective ways to adjust cleaning intensity:
- Change Nozzles: This is the primary method for controlling pressure. Different colored nozzles provide varying spray patterns and pressure outputs.
- 0-degree (Red): Most intense, pinpoint stream for tough stains. Use with extreme caution.
- 15-degree (Yellow): Powerful, narrow spray for heavy-duty cleaning on hard surfaces.
- 25-degree (Green): Medium spray, versatile for general cleaning.
- 40-degree (White): Wide, gentle spray for delicate surfaces.
- Soap (Black/Blue): Low pressure, wide fan for applying detergents.
- Vary Distance from Surface: Moving the spray wand closer to the surface increases pressure, while moving it farther away decreases it. This is a quick and easy way to fine-tune intensity.
- Use a Pressure Regulator (if applicable): Some advanced pressure washer models or accessory kits may include an in-line pressure regulator, allowing you to reduce the output pressure without affecting engine RPM. Check your owner's manual or Simpson accessories.
- Consider a Surface Cleaner: For large, flat areas, a pressure washer surface cleaner can provide even cleaning at a consistent distance, often at a reduced perceived intensity compared to a focused nozzle.
Always refer to your Simpson pressure washer's owner's manual for specific operational guidelines and recommended pressure adjustment methods. This ensures safe and effective use of your equipment and helps prevent damage to surfaces or the pressure washer itself.
