Karcher k 3 washer surges - Karcher Garden

SOURCE: karcher pressure washer motor surging,then

You didn't say if this is a gas or electric machine. I will give suggestions for a gas model. These small engines have air and fuel filters. check both, as it sounds like its getting bad air/fuel mixture. Also try a new spark plug. If this is electric let me know, I'll new some more info.

SOURCE: Karcher Power Washer that surges up and down with water pressure.

Before you start it up:
1. Disconnect the high pressure hose 2. Connect the water supply and turn on 3. Make sure water is flowing through the pump
Start the motor, run for about 10 seconds and then turn off.
Turn off the water supply, connect the high pressure hose, turn water back on, start the motor and away you go.

SOURCE: Electric Karcher pressure washer surging when turned on

Dear firenutt681,
One simple thing you can do, is to check for leaks. Check if hose at machine is leaking. Check gun if it is leaking. You can also check if water still comes out of lance nozzel. These leaks however so small, will cause the machine to surge.
Another reason is due to a faulty SPILL VALVE. This spill valve( often called CONTROL VALVE) will contract when the gun is closed. When it contracts under the enclosed pressure it will switch off the machine by means of a Micro Switch. Now if this Spill valve is faulty it will loose its compression under pressure and puts on the micro switch again. This can be seen once in a while or more frequent, as in your case. I sometimes do service Spill Valves, but mostly I replace them with a new one. I do not know the model number of your machine, but normally you have to open the cover and you should spot the spill valve on the head. Most probably you see a thick wire or a cap containing the micro swith. If you find the micro switch, you have found the spill valve. Sometimes it is a bit hard to pull out the spill valve. Myself, in various Karcher models I remove the spill valve by trying to feed water and put on a bit the machine. In this way the spill valve will be spitted out.
Another reason which makes your machine surge, is leakage from from the detergent inlet.
If you do not see no leakages at all....then for sure it is the SPILL VALVE.
If you cannot do this job yourself or you do not find spare parts...you can continue using the machine as it is...but before closing the gun...switch off the electricity. I only recommend this in an emergency. You do this so that you do not leave the machine surging. This surge will for sure damage the electric motor and the capacitor (assuming it is single phase).
Regards,
Fulltech.

SOURCE: Karcher G 3000 BH Engine Pumping Problem

This may not be a motor problem. It sounds like your pump is not working properly and the motor is just following the pump. First thing to do is check for leaks in the pump, wand hose, gun etc. It may also be a blown water seal inside the pump.

SOURCE: when I squeez the handle the pressure surges.

Hi:
The first thing i would do is be sure there is not a partial blockage in the nozzle.