Pressure Washer Dying

slo50stang

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Hey all,

I recently received a pressure washer for free. The previous owner said it was left at his house after a job. I like tinkering around on motors, especially if I can get it running for a small price, so I took it to see what was up with it. I did a simple spark plug swap and got it running. After connecting a water source to it, it wasn't generating pressure. I ended up buying a new pump for it. Now it generates pressure, but when I pull the trigger the engine dies.

From my research Ive found that its the unloader valve, but the valve is also brand new with the pump. I have not gone through the carb or anything like that yet, but that is my next endeavor.

Now the pump that was intended for the pressure washer is no longer being built, but I went with another pump that was the "new replacement" for the model number. If I remember correctly, the pump is rated approx 200 PSI higher than the OEM pump. So if that could be the issue, Im thinking the unloader valve needs to be adjusted, if that's possible? Or I am also thinking I can swap the old unloader valve to the new pump?

Id just like to get everyone's ideas on it. The pump wasn't an expense I wasn't planning on making, but I think Im getting it close to running properly. Id rather not spend a lot more money on it... At that point Id might as well buy a new washer, haha.

PW Model: Craftsman 580.752340
OEM Pump: 206383GS
Replaced Pump: 510001
 

StarTech

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Back the unloader valve completely off and see if that weak tale 4.5 hp can power the pump. About pump that I worked on in that class has 6.5 hp engine and they never produce the full 2200 psi due the system using 2500 psi tips. I had pressure gauges on them so I do know pressure they are not operating at. What a con job.
 

slo50stang

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I'm assuming its just a matter of loosening the screw on the back of the valve right?
 

tom3

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And don't ever, ever, run the washer until you have water running completely through the pump and hose. A couple seconds of dry run and the pump is toast. Your problem sounds like a lean running carburetor, that pump hits hard when the unloader trips. And for the price of that replacement pump a whole new unit makes sense these days. And electric machines are getting pretty darn capable too, especially with a turbo tip.
 

StarTech

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Especially those vertical units, Horizontals are still worth fixing.
 
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