pressure washer problems

[bob_wood]

This is an unloader valve. :Yours may look a little different, and may cost less.

Northern Tool + Equipment | Error


Pressure Washer Unloader Valve

Some GREAT reading for a guy with a pressure washer problem Thanks !!

bob

 

[J_J]

Bob,


You can probably take it apart , but you need to know some things. The most important is the max pump pressure. You can note the number of threads showing on the adjuster, and reset it to that position, or get a pressure gage and set the pressure to unload before it hits max pressure. You might call the manufacture of the pressure washer and he might tell you the relief setting. If you are going to take it apart, check the shaft of the unloader valve and the spring, and the seat for rust or corrosion.

The best thing probably is to replace the unloader. If you have a pressure washer shop in your area, they will sell you a valve, or they can install it for you.

Since you said the engine runs fine, and the pump is putting out water, It almost has to be the unloader valve. Make sure your gun and the tip are not clogged. Trying starting it with the gun unplugged.

I still have a lot of my commercial pressure washer stuff, just about one of everything that was available, and sometimes two or three of each. The best thing they ever came out with is the turbo nozzle. and the surface cleaners.

 

[bob_wood]

Bob,


You can probably take it apart , but you need to know some things. The most important is the max pump pressure. You can note the number of threads showing on the adjuster, and reset it to that position, or get a pressure gage and set the pressure to unload before it hits max pressure. You might call the manufacture of the pressure washer and he might tell you the relief setting. If you are going to take it apart, check the shaft of the unloader valve and the spring, and the seat for rust or corrosion.

The best thing probably is to replace the unloader. If you have a pressure washer shop in your area, they will sell you a valve, or they can install it for you.

Since you said the engine runs fine, and the pump is putting out water, It almost has to be the unloader valve. Make sure your gun and the tip are not clogged. Trying starting it with the gun unplugged.

I still have a lot of my commercial pressure washer stuff, just about one of everything that was available, and sometimes two or three of each. The best thing they ever came out with is the turbo nozzle. and the surface cleaners.

I took the unloader valve apart and discovered some damage. There is a part that looks somewhat like a needle valve. It rests against a ball bearing. The " needle valve tip was bent and disfigured. I called Northern Tool and ordered a new unloader valve. we'll see ... I'm pretty sure the unloader valve is my problem. Thanks again for all the help J_J

Bob

 

[bob_wood]

I installed a brand new unloader valve and now I get a very low pressure spray for a few seconds then the engine dies. I adjusted the pressure knob on the unloader but it doesnt make any difference. Any way I can verify that the pump is working properly ?

Bob

 

[J_J]

Make sure you have good input water pressure . Check the inlet filter. Check and see how much water is coming out the pump with hose disconnected. Disconnect the pump from the engine, and run the engine for a while. If the engine funs good, then the problem is in the pump. If you have a pressure gage that you can plug into the pump, that will tell you if it is putting out good pressure. If the pump is putting out good pressure, the relief/unloader valve will bypass or relieve if the gun trigger is off.

 

[J_J]

I unhooked the pump from the engine and the engine seems to run fine but the pump load is somehow killing the engine. Guess I should be troubleshooting this problem with the pump hooked to the engine. With the pump hooked up, I do see the choke lever go to full choke when the engine stalls.. any idea what That means? Does it on its own. Thanks for the input Tom

bob

The choke lever on that Honda is only to start the engine, and after starting, it does not move. Maybe you have the choke lever in the on position, which will and try to kill the engine.

 

[bob_wood]

Make sure you have good input water pressure . Check the inlet filter. Check and see how much water is coming out the pump with hose disconnected. Disconnect the pump from the engine, and run the engine for a while. If the engine funs good, then the problem is in the pump. If you have a pressure gage that you can plug into the pump, that will tell you if it is putting out good pressure. If the pump is putting out good pressure, the relief/unloader valve will bypass or relieve if the gun trigger is off.

I checked the inlet filter and it looks clean. The engine runs good when it is disconnected from the pump. When I disconnect the wand hose from the unloader valve, I get water thru the input filter and out the unloader , low pressure ( probably just going thru the bypass hose). The engine will stall in this configuration too so guess my wand and hose are not clogged. I dont have a pressure gauge. My engine choke is only on to start the engine. I'm going to work on it some more this morning. Might have to take this thing to somebody that knows more about it than I do . Thanks for the input J_J.

Bob

 

[ampsucker]

i believe that engine has a demand type govener? it definitely works harder when pumping under pressure than when free spinning with no load. i'm starting to suspect a clogged carb jet or as previously mentioned a gunked up fuel shut off valve or fuel filter. it sounds like the engine only dies under load when it is getting the request from the govener for more fuel.

any way to load the engine while the pump is disconnected?

amp

 

[bob_wood]

i believe that engine has a demand type govener? it definitely works harder when pumping under pressure than when free spinning with no load. i'm starting to suspect a clogged carb jet or as previously mentioned a gunked up fuel shut off valve or fuel filter. it sounds like the engine only dies under load when it is getting the request from the govener for more fuel.

any way to load the engine while the pump is disconnected?

amp

That Does make alotta sense to me amp. The engine ran when i disconnected it from the pump but it seemed to be a little rough. You got me thinkin now. Dont know how i could put a load on it off hand but thanks for that idea. Wish I could get this thing going , I need it. All my equipment is real dirty. When the engine runs ( with pump on it ) it goes up to full rpm, stays there for a few seconds... then its like ya flipped the off switch, it dosent bogg down at all, it just dies.
Bob

 

[ampsucker]

my honda pw has a governer arm that attaches to the carb linkage by a series of springs. i think it is internally demand actuated. if yours has this, you might try manually activating it with your finger to see if the motor can run at max rpm without the pump attached.

passing this test should eliminate any clogged high speed orifices inside the carb or a clogged fuel line as your problem. it might be running ok at idle or mid rpm, but starve for gas at WOT (wide open throttle).

doing this test is the equivalent of revving an engine with accelerator pedal only pressure washers don't a "throttle" per se, since they are designed to run at single rpm all the time. the governer manages the fuel to meet the demand and hold the engine at the correct rpm to produce the oem pressure and flow specs for the pump. you can trick it by pushing the governer arm with your finger to open up the carb.

there may also be an adjustment set screw on the governer arm that could be out of adjustment. if it passes the WOT test, you might try experimenting with that setting. if, for example, you put a load on the engine and the govener arm does NOT respond properly, the engine would die because it's not getting enough fuel to power the load. adjusting could help this or the internal workings of the govener could be messed up or gummed up and a good disassembly and cleaning might help if you diagnose that to be your problem.

amp

 

[J_J]

That Does make alotta sense to me amp. The engine ran when i disconnected it from the pump but it seemed to be a little rough. You got me thinkin now. Dont know how i could put a load on it off hand but thanks for that idea. Wish I could get this thing going , I need it. All my equipment is real dirty. When the engine runs ( with pump on it ) it goes up to full rpm, stays there for a few seconds... then its like ya flipped the off switch, it dosent bogg down at all, it just dies.
Bob

Bob,

I am assuming that you have checked the Cylinder head pressure and the oil is above the oil shut off level. If the engine runs fine for a minute or two and suddenly dies, with pump off, then it sounds like fuel starvation. I am thinking that when you start the engine, it is running on the fuel in the carb. and when the bowl is empty, the engine will die. Make sure that the float and seat are working properly. Take the bowl off and see if gas is coming into the carb. See if there is any water in the bowl. I believe that there is a bowl bleed screw in the side or bottom of the carb. Then check the floats ability to shut off the fuel. Not enough or to much fuel will choke or kill the engine. Since you said it was running rough, a clogged main jet could cause your problem. I would take the main jet out and check it with a wire and blow through it to see if the jet is clear. About the only other thing I can think of is to see if the spark is there at all times. Did I mention to check pump oil. It should be non-detergent 30w.

I have a similar pressure washer with a 13 hp Honda engine driving a belt driven pump. I have done all the things that I am telling you.

The only way to test your pump is with a good running engine. If your pump can put out 5 gpm, take a 5 gal bucket of water and run a small length of stiff hose in the bucket and the other end connected to the input and start the engine, If the pump can pump the 5 gal out of the bucket in 1 min, then the pump is working. Don't expect very much pressure out of the pump, until you attach the gun and nozzle.

If the engine will stay running and the pump goes into bypass made, with the gun trigger in the on position, then the gun is clogged, or the tip is clogged. Remove or change the tip and see of any water is coming out.

Are you starting the engine with the throttle in the fast mode. You should also pull the trigger on the gun before you start in order to have a clear path for the water to flow. It takes a lot of force to overcome the spring tension of the unloader. A pressure washer engine at idle may not be able to overcome this.

 

[bobcatoh]

Change the spark plug!

 

[bob_wood]

Bob,

I am assuming that you have checked the Cylinder head pressure and the oil is above the oil shut off level. If the engine runs fine for a minute or two and suddenly dies, with pump off, then it sounds like fuel starvation. I am thinking that when you start the engine, it is running on the fuel in the carb. and when the bowl is empty, the engine will die. Make sure that the float and seat are working properly. Take the bowl off and see if gas is coming into the carb. See if there is any water in the bowl. I believe that there is a bowl bleed screw in the side or bottom of the carb. Then check the floats ability to shut off the fuel. Not enough or to much fuel will choke or kill the engine. Since you said it was running rough, a clogged main jet could cause your problem. I would take the main jet out and check it with a wire and blow through it to see if the jet is clear. About the only other thing I can think of is to see if the spark is there at all times. Did I mention to check pump oil. It should be non-detergent 30w.

I have a similar pressure washer with a 13 hp Honda engine driving a belt driven pump. I have done all the things that I am telling you.

The only way to test your pump is with a good running engine. If your pump can put out 5 gpm, take a 5 gal bucket of water and run a small length of stiff hose in the bucket and the other end connected to the input and start the engine, If the pump can pump the 5 gal out of the bucket in 1 min, then the pump is working. Don't expect very much pressure out of the pump, until you attach the gun and nozzle.

If the engine will stay running and the pump goes into bypass made, with the gun trigger in the on position, then the gun is clogged, or the tip is clogged. Remove or change the tip and see of any water is coming out.

Are you starting the engine with the throttle in the fast mode. You should also pull the trigger on the gun before you start in order to have a clear path for the water to flow. It takes a lot of force to overcome the spring tension of the unloader. A pressure washer engine at idle may not be able to overcome this.

J_J did check the pump oil level and engine oil level but not equiped to check head pressure. The engine runs ok with pump disconnected. I took two bowls off the engine and they looked clean and gas Was coming into engine. If I disconnect hose and wand , water comes out of unloader valve while engine is running but engine stalls after a few seconds...so that would eliminate hosw, wand. nozzle being clogged, correct. ? I do pull wand trigger to release pressure before starting engine.


Really appreciate all the input and help guys. With my schedule being quite busy and my limited knowledge of pressure washers I think I am ready to take the whole problem to my local pressure washer repair place ( if I can find their address ) I have done about all that I can and have time for. Again, thanks for all the replys

Bob

 

[bob_wood]

Change the spark plug!

I can start the engine with one or two pulls every time and it runs for a few seconds. Would the engine want to start at all if the plug was bad ?

Thanks for the input

Bob

 

[Taylortractornut]

My hot water washer did the same thing with my Vangaurd engine I tried everything not wanting to take it in for repair. come to find out it was a small piece of plastic bag in the tank it would suck down infront of the fuel line after running a minute. It turned out it was the little plastc piunch out from a plastic bag. when I filled up at the staion that bag was used to cover the nozzles is my best guess.

 

[J_J]

I unhooked the pump from the engine and the engine seems to run fine but the pump load is somehow killing the engine. Guess I should be troubleshooting this problem with the pump hooked to the engine. With the pump hooked up, I do see the choke lever go to full choke when the engine stalls.. any idea what That means? Does it on its own. Thanks for the input Tom

bob

Bob,

You said you saw the choke move.

The choke lever is not supposed to move except when you move it. The only thing that should move around the carb, is the governor. If it is touching the choke lever in any way, it might throw the choke on and kill the engine. Since the trouble started, have you been able to run the engine for at least 15 min?

 

[bob_wood]

Bob,

You said you saw the choke move.

The choke lever is not supposed to move except when you move it. The only thing that should move around the carb, is the governor. If it is touching the choke lever in any way, it might throw the choke on and kill the engine. Since the trouble started, have you been able to run the engine for at least 15 min?

when i had the original unloadervalve on i remember seeing the choke lever move to the closed position ( suddenly ) when the engine stalled. i'm not sure that happens now... When I unhooked the pump I run the engine for ....maybe a minute.... seemed ok so I hooked the pump back up. Think I should unhook the pump again and run the engine for awhile ? Problem is there I dont have a load on the engine that way. If I could isolate the problem to the pump or to the engine would be a Great start ! Hate to give up on this thing .... but I have to work tomorrow to keep the wife happy...

not sure which piece would be the govenor ... maybe i'll pull the breather and stuf off and see if I can see anything that looks like it is rubbing together...

Thanks J_J

Bob

 

[J_J]

Yes, run the engine with no pump on, and no air cleaner so you can see if anything is moving . You will know by the sound of the engine if it is running correctly. If it can run 15 min, move the throttle lever from fast to slow and back several times.

The governor is a lever attached to a shaft going into the engine, close to the bottom of the engine. There will be some springs on the top of the governor lever. It tries to regulate the speed that you set by the throttle. While the engine is running, you can tell if the governor mechanism is working correctly by pushing the governor lever. The engine will speed up and try to push the lever back where it was. To set the correct governor speed, you need a tachometer and the engine manual.

http://www.hondaengines.com/Engines_owners_manuals/ownersmanuals/31ZH9600.pdf

http://www.honda-engines.com/Engines_owners_manuals/ownersmanuals/37Z5F602.pdf

Check the sediment bowl as on page 25.

One other item. Take off the exhaust deflector cap and clean the spark arrestor. If it is clogged up, the engine will not run good, perhaps stalling out.

 

[bob_wood]

Yes, run the engine with no pump on, and no air cleaner so you can see if anything is moving . You will know by the sound of the engine if it is running correctly. If it can run 15 min, move the throttle lever from fast to slow and back several times.

The governor is a lever attached to a shaft going into the engine, close to the bottom of the engine. There will be some springs on the top of the governor lever. It tries to regulate the speed that you set by the throttle. While the engine is running, you can tell if the governor mechanism is working correctly by pushing the governor lever. The engine will speed up and try to push the lever back where it was. To set the correct governor speed, you need a tachometer and the engine manual.

Ill give that a try J_J, maybe tomorrow after work. At least I can try to find the governor and see if it seems to be working. Like to get this fixed myself ( with Your help ) as I have spent all my money on a new valve I have the Honda GX390 13HP I bought the unit in 97 .... Ive never done anything to the engine except change the oil ... and blow out the airfilter... Think I ought to put a new plug in it ? The engine stops so suddenly and consistantly ....seems load related to me... but I'll havea closer look at the engine. The link you sent is the manual I have . I have checked sediment bowl and everything I could see in the manual. I have not tried fresh gas yet.....

Thanks for the help !!

Bob

 

[CCWKen]

I hate to be the one to say it; But, I told you so. I think your problem is fuel flow. When I mentioned pressurizing the tank, this temporarily clears any blockage in the fuel strainer. The real fix would be to disassemble the strainer and clean it. It's item #23 in the picture below.