Powerwasher pressure regulation question

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This is your tax dollars at work. I bought this powerwasher used from the US military. I suspect that they wrote it off because the gas line from the tank to the carburetor was rotten and leaking. Why else would they write it off? If, say, the engine wore down and that was the reason, the line would not be leaking. I replaced the line and the engine started on the second pull. It is supposed to be a bad ass power washer, up to 3,000 PSI, with the Briggs and Stratton 11 HP Industrial/Commercial engine.

First Question: the engine goes faster and slower every 6 seconds or so, maybe varying speed by 30%. Why would that be the case.

Second question: how would I regulate water pressure on this beast? There is no obvious valve that I could touch. I think that 3,000 PSI is serious pressure and I want to get some opinions before I start messing with the pump. Maybe I should torque the nut on top of the pump, shutting off bypass.

(Click on the thumbnail images to enlarge)

Reply to
Ignoramus17028
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Usually a sticking/worm governor. If it was the fuel mix, they usually rev up + down every couple of seconds.

Unscrew the nut to reduce pressure.

Reply to
Moray Cuthill

I suspect they wrote it off because it is twenty years old, at least the date code on the engine indicates it was manufactured in '85.

The engine changing speed is got to be from a out of adjustment governor, or worn linkage. Possibly a dirty carburetor or out of adjustment fuel settings.

To adjust the water pressure back off the nuts on the relief valve. It is the unit mounted to the side of the pump where the discharge hose comes out, with the orange washers. It looks to be a pretty good unit other than the obvious starter problem! Most of these gas powered units see little use so the chances are the pump and engine are in good shape. Greg

Reply to
Greg O

Thanks. My current pressure was way below 3000 psi, and yet I definitely needed your advice about a rain suit. :)

I will try playing with higher pressure tomorrow. Unfortunately, the pressure gauge is missing the pointer, so I cannot know the exact pressure. I may try to put it apart to see if it can be easily restored, the pointer is on the bottom of the gauge.

Would it be correct to say that 3000 PSI is supposed to shred wood?

i
Reply to
Ignoramus17028

Quite possibly.

I see. I will try to look at it closely to understand it.

Thank you.

Do you mean a governor problem? The unit starts up fine.

They look pretty decent.

Thank you!

i
Reply to
Ignoramus17028

It would be correct to say that 3000 PSI will demolish rotten wood. Sound wood, hit at a glancing angle, might not be a problem.

I pressure washed my fence and grape arbor with 2300 psi water and had no problems with sound woood.

Reply to
Jim Stewart

keep a distance from rubber parts and seals on hydraulic cylinders.. also radiators and anything else that 3000 lbs will shread. Get a good rain suit until you learn how to point that thing.. Watch out for the corners/ :)

John

Reply to
john

In your pics the pull starter is missing. Does the engine have electric start too? Greg

Reply to
Greg O

Now I understand your question. No, it has rope start. Considering that it easily starts on the first pull, I do not mind it that much.

i
Reply to
Ignoramus17028

Shawn, what would be the practical examples (not necessarily around the house) of real life use of 3,000 PSI for pressure washing.

i
Reply to
Ignoramus17028

Ok, I just saw that the rewind starter assembly was missing. There are screws and a starter clutch for a rewind, plus some paint missing from where it mounts. B&S made the I/C series engine with a place to wrap a rope to start it if the recoil starter breaks. No big deal as long as it starts well. Greg

Reply to
Greg O

I only know the first answer: If the air filter is clean... Most likely is that the governor spring isn't firm enough, or is too loose. Look around the engine's carb until you see the governor spring. Might have to take off some shrouding and the air filter to get to it. The tab that the spring hooks onto is usually bendable, but sometimes has a lever with a clamping screw. However it adjusts, while running the engine, move that anchor so that it stretches the spring a bit. If the RPMs settle out, problem solved. If the hunting gets worse, go the other direction with the anchor. That should do it. If not, depends on what kind of governor you have--either air vane or internal. You can ID the internal kind because you have linkage going off to a small shaft poking out of the crankcase. The air vane type will simply have a plastic flag next to the flywheel under the shroud. Make sure the paddle can move freely on its shaft and isn't cracked. Cracks respond well to JB Weld. If it's internal, it's somewhat complicated to adjust and I don't want to write it all out if I don't need to. (: If it isn't your governor spring or linkage you'll likely need to clean out the carb. First try running fresh gas in it--that'll take care of about half the "bad" carbs out there. But I doubt it's a carb problem since you didn't say anything about the exhaust and I don't see any clouds in your photos. Normally if a carb is causing hunting problems your engine will rev up, run rich, rev down, run lean, repeat. That would cause nasty exhaust. I think. Also, I saw in your photos that you're running it without any pull starter cover in place. That starter clutch's (that little square shaft poking out of the flywheel hub) plate holding the square stub shaft usually is only retained by a slight friction fit and the pull cord assembly sitting on top. It's not terribly likely, but running without anything on top of it can let it come apart on you. Take a look and make sire it's got something holding it on before you run it again. Looks like the pull-start wheel thingamajig holds it, but I can't quite tell from the photos.

Reply to
B.B.

On Mon, 7 Mar 2005 00:36:40 -0500, "Shawn" vaguely proposed a theory ......and in reply I say!:

remove ns from my header address to reply via email

And do NOT use it to wash down even clothed parts of your body.

I saw some guy using one the other day to wash cut lawn grass off himself. It was only an eletric one, but they are still up at 1500 psi!

We had some kids electricuted over here, too because they were playing with one of thes things, and it shorted out.

nnnggg!

Reply to
OldNick

A 3000 psi pressure washer is made for cleaning things like heavy equipment, not really for "around the house" type stuff. Backing off the pressure by decreasing the spring pressure on the bypass valve would be my recommendation. When the job calls for it, 3000 psi is great to have, just hold on to the gun tightly.

Shawn

Reply to
Shawn

I got it, thanks.

i
Reply to
Ignoramus17028

THANK YOU, I printed out your post for tomorrow.

igor

Reply to
Ignoramus17028

Yes! Beware of airconditioning condenser fins too ... makes them flat fast!

Glenn

Reply to
Glenn

Does it cycle while you spray or just sitting ? Martin

Reply to
Martin H. Eastburn

I think that it cycles just sitting.

i
Reply to
Ignoramus26383

One thing I forgot to add: if you remove the air cleaner, on some carbs the tip of the screw is used to seal off a passage. If you take off the filter and the engine runs horribly all of a sudden, stick the air filter's screw in all by itself and it should fix that. Put it in just enough to fix it--if you keep turning it until it stops on its own you can put it in way too far and knock out a gasket. As best I can tell your engine doesn't have one of the carbs that would have that problem, but it's something to watch out for.

Reply to
B.B.

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