unloader question

bulletproof

bulletproof

New member
As some of you may have read me say before , I am basically new to the pw business. I must say that these bb's have been a valuable source of info and learning. The question that I have now is regarding unloaders. I own a 4hp briggs and stratton quatro pw rated at 1740 psi. This is my first machine and in reading the manual it says that it can do 5 gpm max. I want to find out if any one knows where the unloader is on this machine and how I can adjust it to increase the gpm. Tried the company's website but it doesn't say and the diagram in the manual doesn't either
 
You'll never get 5 gpm out of that machine. You've probably got a 2.2 - 2.5 gpm pump on it, and that's all you'll ever get.
 
The unloader does NOT increase the GPM ever. It does bypass water to increase pressure though.

It is a PRIMARY SAFETY DEVICE and should never be adjusted from factory settings.

All pumps are positive displacement where at a given RPM they will always pump the same amount of water. To increase flow you need to increase RPM or change to a pump rated at whatever flow you desire at the available RPM.

However, there are limits. With your 4hp Quatro engine (not one of B&S's better ideas, ask any small engine repair guy) will give you 5 GPM at 900 PSI running with the appropriate pump, not the one you have though (2.7 @ 1740).

UNLEARN TWO VERY USELESS PIECES OF INFORMATION... CLEANING UNITS and PRESSURE. Any professional pressure washer will tell you that flow cleans and pressure helps; more of the former is better than more of the latter. Flow is related to horsepower; more of one gets more of the other.

As to 'Cleaning Units', they were designed by a marketing department at a supplier to 'Big Boxes' to baffle the consumer. Pressure is the easy part of the equation and requires minimal quality engineering. Also a 4 GPM @ 1000 PSI machine will clean very fast circles around a 1 GPM @ 4000 PSI machine; every time.

Hope this helps? Cheers.
 
I use the garden hose compared to a fire hose approach when I refer to GPM. Same pressure different flow rate.
 
Power Washing With Gpm
 

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Sometimes they will use an over rated pump on a smaller engine to get certain psi and gpm on a machine. In other words they will make a machine with the components available to them and the outcome will be less than the pump rating.

Here is another example that has nothing to do with pressure washing. Let's say you have a Kenwood Amp that puts out 50 watts RMS. Sometimes you will have speakers that handle 150 watts. The speakers will never put out 150 watts with an amplifier that is only 50 watts.

The Amplifier is the Engine on your pressure washer and the Speakers are the Pump
 
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