3.5 v 4 gpm

Found a guy selling a 3.5 gpm 4000 psi cat pump which he says works …he took the motor for anouther project…I currently run a 4gpm 4000 psi comet…is there much difference between the flow ??? I know the minimum for a professional washer is 4 gpm …would this pump be a waste of money or a big step backwards …or would you not really notice a half a gallon ???

Is your comet running well? Are you just looking to have a backup pump?

If the comet is in need of replacing, and this is all you can afford right now until you can get a few jobs done, then you can get by with a 3.5. I did it. But you will probably notice some decline in performance.

If you’re looking to upgrade, get a gear drive udor at 5.5gpm. It will bolt right onto your motor in place of the direct drive comet pump (so I am told).

Comet is running good …the guy only wants 50 bucks for it …just wondering if I should buy it or use the 50 bucks towards a better upgrade …I just ordered my 18 inch hammer head!! Not the best but I’m excited

Although $50 is cheap for a pump why waste the money on a smaller pump. You should be saving a little money from jobs and if/when your current pump needs fixing or replace buy a bigger better pump. Its only $50 so it wouldnt hurt having it, it would just take longer to clean with it.

Also you should have gotten the 16in whisper wash surface cleaner. Way better than the hammer head and not much more $.

My supplier has the 19 in whisper wash but it’s twice the price and I needed a surface cleaner …I’m sure this won’t be my last surface cleaner I figure I can sell it when I’m ready to upgrade…the are so many people washing in my area I should be able to get almost what I paid out of it , close enough anyway …

I didnt say the 19in classic. Your running 4gpm, and the optimal surface cleaner size is a 16in. The 16in whisper wash (aka: eagle wash) is the best to run and cost about $400. Running a larger surface cleaner means moving a lot slower.

@Donte55 hey thanks I see the one you are talking about now … that may have been a better choice for me …hopefully next year I’m going to step up to a 5.5 gpm machine …I’m a Impulse shopper !!

I have a 4 gpm unit that puts out 2500 psi. What would be a good starter surface cleaner for me? Folks ask if I can do their driveway and I’m like “yea!” But then I realize I don’t have the right tools for it

Whisper wash classic.

Even though 4gpm can move the classic, the 16in whisper wash is the best choice.
General rule is 4in for every gallon you machine makes.

Im curious though what brand your machine is and what HP your engine is making for only 2500 psi

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Honda gx390 13 hp and comet zwd4040. I have a 275 gal buffer tank that I keep at 100 gal with my Hudson float. I’ve tried setting my unloader to get more pressure but it just makes my engine bog and die. I’m baffled. I would really like to be putting out about 3500 psi because the pump has a 4000 psi max. Should I be looking into a new pump in the near future?

What I found

Desired PSI X Desired GPM X .0007 = HP Required

Based on that it puts me at 9.8. My motor is a 13hp. Maybe I need to set my buffer tank higher. To around 150/175 gallons? In theory that would create more pressure at the bottom of my tank. :thinking:

@Alabama I have the same pump I’m putting out 3500 psi with a little room to spare …maybe your seals are bad and need replaced or maybe your unloader is not set right or not working…and maybe also you are using the wrong orifice on your tips …my input on. Your low psi

Is your machine belt, gear or direct drive?

Yeah definitely enough engine… Something’s definitely wrong.

I’m just using the standard tips that come with all machines. Yellow, green, white. It is a direct drive. I will try to make some more adjustments on the unloader tomorrow and see what I can come up with. How hard is it to replace the seals in the pump? I bought it used. I figured something has to be off. Basically I squeeze the trigger the motor bogs like it’s trying- good pressure comes out for a second. The motor struggles-bogs. I release pressure and sometimes it’ll chug back up to high rpm or it’ll die. The motor sounds like it doesn’t like the load being put on it. Which makes me wonder what should i try to fix first.

Another question. Should I go ahead and just replace the pump seal kit or the oil seal kit? I would assume just the water seal kit. ??

Hook up your pressure washer to a house spigot and see if that fixes the problem.
Direct drives dont pull/suck water that good, so you are probably starving the pump.

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That probably should have been the first thing i did. I will do that this evening. I ordered a seal kit last night. Man I hope that’s not what it is because I took a lot of time setting up my buffer tank and plumbing. Do you think I should reduce the size of pipe coming from bulkhead? Currently it’s a 2" to 1 1/4" to 1 “. Wonder if I should just go 1 1/4 down to 1” to increase pressure. (Like I had before :expressionless:). Here’s a pic