Karcher Pressure Washer Pump 3000psi - Horizontal Shaft 9.120-021.0 (9120021)

I had some problems sliding the pump onto the shaft. The slot key kept sliding down preventing the pump from going all the way down. I used a screwdriver, preventing the slot key for sliding down to far. Then input my bolts on and tighten the pump down onto pressure washer.After making some minor adjustment, new plug, and air filter, it runs outstanding. My Karcher CG160 is about 20 years old. It alway frustrated me because of the air or lack of air in the line. This new pump gets a thumbs up. I'm 74, and was not the sharpest nut on the thread. I watched some YouTube videos on this product, consulted with a friend. If I can install this anyone else with limited skills can. Your product does the job.

Nice quality, installed easily, everything fit like factory. Good value, sturdy , holes lined up on the engine.

So the OEM pump was building pressure then dumping. The back pressure seemed to be to high for the pump. Replaced the pump with this one only to find it doing the exact same thing. So I dissected the original pump ( DO NOT open up your pump, it is pressure sealed and the oil inside will leak out unless you know it is bad inside) to find what the issue was and found a ring of ball bearings in the cylinder was shredded. Another few days past with tinkering and researching. I replaced the 40ft hose with a 25ft hose... same problem. Testing it from the pump to the tip, the surging didn’t occur with just the pump, nor the hose, nor the gun, but it did start surging when the tip was installed. I should have know that there were other tips with different diameters. I called around my area to pressure washer repair shops which I found by going to Karcher.com/help where you can find a map of the dealers who either work on or sell Karcher pumps. One of the shops told me to call who I bought the pump from-Tool Barn/ through Amazon. I got directed straight to the pressure washer specialist named Jeff. He said that this is a very common issue and all it takes is a different size tip/orifice because the smaller tips/ orifices make too much back pressure which causes the unloaded valve to open dumping all the pressure creating loads of frustrations. He said that these pumps run best with .035 tips/ orifices. I measured the tip that I had and low and behold it was .030 orifice which is too small causing the dumping of pressure. I had some larger tips on another pressure washer, put one of those on, and all issues were solved!!!If this pump is building pressure for 2-3 seconds and then losing the pressure......... BUY .035 TIPS/ORIFICE IT WILL SOLVE THIS ISSUE.

OK, so people are ticked off because this is some 3rd party part.... did they not bother to read the item description? do they not know the entire machine is made by 3rd parties in China?Totally fits my Karcher K 2400 HH. Installation was about 15 min. Works like a charm.

Bolted right up, fixed the issue, pumps like a champ. Took me less than 10 minutes. Way cheaper than Karcher direct.

The media could not be loaded. Original pump lasted 17 years - this one lasted 5 months and complete failure with keepers on top of springs. Easy to install and was direct replacement but quality is CRAP or maybe a little worse. Hate to throw out a perfectly good Honda motor but at the price of these for 5 months use guess it’s time for a new pressure washer.

The pump fit my Karcher model G 2400HH. I had bloody hell getting the old one off. Wound up disassembling the old pump as completely as possible while still stuck on the motor shaft. Got it down to the point where more penetrating oil and ball peen hammer whack and pull process finally got it moving a fraction of an inch at a time. Once off, it was not much to installing the new. Start the motor and wrap some sandpaper on shaft to knock all the rust off and polish up smooth. Apply a liberal dose of Locktite on shaft, position key in slot of shaft and slipped the new one right on. The shape of the new pump on the bottom side kind of blocks access to using any kind of socket with 1/4" allen, so had to use plain old allen wrench a few turns at a time to get it cinched up tight. I am amazed at how much quieter the the run noise is. However, it seems to me the pressure is noticeably less than what I had before. Kinda disappointed about that, but it works. Need to put some time on it to see if it improves.BTW, I ordered a set of new nozzles off Amazon from Obecome. They are knock-offs and caused immediate surging (no markings so no way of telling orifice size). Obecome is not going to respond. Think they're made in China. Don't waste your money. I ordered another set from Home Depot for $13. Same size 3.0 orifice as my original nozzles.

The cost for all the parts to rebuild the original pump was about the same as buying this entire unit and just swapping it out. Removing it from the keyway shaft on the motor is not that easy after it's been on there for a while, what can be done with two prybars and some penetrating oil. This is an updated version of the original pump with a built-in pressure relief that the old unit did not have.