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SIMPSON

Simpson Cleaning 4200 PSI Gas Pressure Washer, 4.0 GPM Power Washer for Commercial Use, Honda GX390 Engine, 50-Foot Steel-Braided Hose, Aluminum Series, 49-State (ALH4240)

  • Based on 1,535 reviews
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Availability: Only 4 left in stock, order soon!
Fulfilled by CPO Outlets
Arrives Apr 12 – Apr 17
Order within 13 hours and 43 minutes
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Style: 4200 PSI Honda GX390


Features

  • Professional Performance: Easy-to-assemble and easy-to-start with its HONDA GX390 engine commercial series engine, the Aluminum Series power washer is great for contractors who specialize in deck cleaning, wood restoration, and all professional services
  • Power and Durability: A powerful, reliable, maintenance-free CAT Industrial triplex plunger pump delivers 4200 PSI at 4.0 GPM and includes thermal relief to prevent overheating
  • Sturdy and Portable: The aircraft grade aluminum platform with brushed extruded aluminum tubing offers durability and corrosion resistance; 13-inch premium pneumatic tires deliver ease of maneuverability across various terrain and uneven ground
  • Includes Quality Simpson Accessories: Monster 3/8-inch x 50-foot high-pressure hose is kink- and abrasion-resistant; 5 Quick connect nozzle tips: 0, 15, 25, 40 and Soap; 16-inch steel wand/lance; Professional spray gun with safety lock-out
  • Important Notes: 49-State Compliant; Pump/Hose Connection: Threaded M22 connection

Description

The SIMPSON Aluminum Series pressure washer 4200 PSI at 4.0 GPM is great for construction, equipment upkeep, and facility and fleet maintenance cleaning. With a powerful HONDA GX390 engine, reliable CAT triplex pump, and ultra lightweight aircraft grade aluminum frame, this pressure washer is the optimum blend of maneuverability and performance. The ALH4240 also comes with a 50’ hose, ergonomic spray gun, and 5 Quick Connect nozzles. Designed to meet the rigorous demands of the cleaning professional, the SIMPSON Aluminum Series frame is crafted of 100% aircraft grade aluminum, making it lighter in weight than most steel frame pressure washer designs. Perfect for contractors who specialize in deck cleaning, wood restoration, paint preparation, graffiti removal and all other professional cleaning services. The SIMPSON Aluminum Series designed for optimum performance in the harshest environments. 10 Year Limited Frame Warranty, 5 Year Limited Pump Warranty, 3 Year Limited Engine Warranty. Includes: Pressure Washer, Hose, Gun, Wand, 5 Quick connect nozzle tips, Detergent siphon tube with filter, Engine Oil, Quick start set up guide, Owner's manual.

Brand: SIMPSON


Power Source: Gasoline


Color: Red


Item Weight: 124 Pounds


Hose Length: 50 Inches


Product Dimensions: 38"L x 23.5"W x 29"H


Tank Volume: 2.5 Gallons


Maximum Flow Rate: 4 Gallons Per Minute


Global Trade Identification Number: 45


UPC:


Brand: SIMPSON


Power Source: Gasoline


Color: Red


Item Weight: 124 Pounds


Hose Length: 50 Inches


Product Dimensions: 38"L x 23.5"W x 29"H


Tank Volume: 2.5 Gallons


Maximum Flow Rate: 4 Gallons Per Minute


Global Trade Identification Number: 45


UPC: 879399001345


Wand Length: 31 Inches


Item Weight: 124 pounds


Manufacturer: SIMPSON


Item model number: ALH4240


Is Discontinued By Manufacturer: No


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Apr 12 – Apr 17

This item is non-returnable:

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

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Leasing options through Acima may also be available during checkout.

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Similar Products

Top Amazon Reviews

    • This thing is a beast!
I read a LOT of reviews here on Amazon and other online resources before deciding to make such a sizable investment in this 4200 PSI/4.0 GPM machine. This is not my first pressure washer, but my third actually. Each time I upgraded in both PSI and gallons per minute. This is my first pressure washer that is categorized as commercial use. Having finally taken the time to put this machine to the test, I can honestly say this thing has more than enough power to satisfy the average homeowner or DIY’er. As I said in the title: this thing is a beast! Mine arrived complete and undamaged. Other reviewers reported scratches and dents but that was not my experience at all. Assembly was quick and easy. My shipment contained a quart of Amsoil synthetic 10W-30 for the engine crankcase but I have seen other reviewers that got their oil in a plastic pouch. Once assembled, the crankcase filled with the supplied oil, and the fuel tank filled 1/2 way, I hooked up the garden hose and bled the air out for 30+ seconds as recommended. Set the throttle to half-way and closed the choke and gave the starter a quick pull and it fired right up on the first attempt. After allowing the engine to run at partial throttle with the trigger open to keep the water flowing and the pump cooled for a few minutes, I increased the engine speed to approximately 3/4 and started cleaning the concrete patio as my first project with this unit. The pressure even at less than wide open on the Honda GX390 was more than enough to get the accumulated grime blasted off effortlessly. Next up, I connected my 15” surface cleaner which really sped up the process. The 4240 pressure and water flow are a perfect match for the Karcher 15” surface cleaner. With all of the positive attributes of this machine, there is one thing that I feel is a negative: the hose. It’s more than long enough for most jobs but the stiffness makes moving around with it a real challenge. Given the higher than average PSI capabilities of the ALH-4240 it’s not surprising that the pressure hose is more on the stiff side, but as others have commented, it would be a good idea to upgrade to a better hose. Honestly, at this price point, a better quality hose should come with it. Overall, the ALH-4240 is a great pressure washer that has all of the power that the average person could want for DIY use. The high PSI and GPM make short work out of even the toughest cleaning projects. Time will tell if it lives up to the Simpson advertised claims of dependability and reliability. ... show more
Reviewed in the United States on September 17, 2024 by Kenneth B.
    • Honda + CAT pumps = Quality
Review Image by MMADD MMADD
I'd like to start out by saying I own and operate a power washing company and this is my main work horse every day. I've owned the machine for a full year now so I figured I'd get Amazon my review. I've used this machine for over 6-700 hours in 100 degree heat to down into the 40s. It has never given me one hiccup or issue. I've changed the pump oil 3 times and the engine oil twice. I gave it a new Denso spark plug just because I was doing the maintenance on it. Pulled spark plug could have easily gone wagly longer. Machine starts on one pull every time. I do recommend the use of non ethanol gasoline and your carborator will never give you a problem gumming up. Do the maintenance! Honda delivers and excellent product with the GX390. I've used them for years. CAT pumps are top of the line and this little pump proves its worth every day. There are some cons, not with the machine but with the frame. The rubber feet that come on the front to support the machine and dampen vibration completely left chat maybe a week into using it and I leave the machine on the truck when it's in use soni had to improvise with some rubber pads so it wont vibrate a hole into the composite truck bed. The delivery people (UPS) delivered it upside down, thankfully the machine had no issues. Frame was bent up pretty badly to the point where the detachable handle didn't fit, I had to force it on and now it's stuck and the wheel was severely crooked rubbing on the side of the frame. I had to kick that like a mule to straighten it to the point where the rub is minor now. I'm not driving the thing cross country so this doesn't bother me at all. They did not pad the machine in the box barely at all. I believe they could do a lot better there. I looked past it and the machine works flawlessly The accessories that come with the machine were mostly junk. I always throw the gun in a box because they always fall apart after a month or so. The hose lasted a long time. I do not use the on board injector because my chemicals are not good for them so I always use my own downstream injector. Never fails with these machines that the exhaust housings rust out on them and usually fall apart after a couple years. They make all the parts for this machine still thankfully. ... show more
Reviewed in the United States on April 20, 2024 by MMADD MMADD
    • I do not recommend this machine or the company that makes them.
Review Image by German German
Review Image by German German
Review Image by German German
Review Image by German German
Review Image by German German
Review Image by German German
Review Image by German German
When I received it, it came with a few bumps and I tried to return it but in the end I didn't do it for work reasons, 6 months have passed and suddenly the water pump was used. 3 months ago I sent the guarantee that they provide by phone. The guarantor just says that they still do. I do not receive the answers from the Simpson company I really do not recommend this type of brands, you have to play it safe like Sthil. I make this new review of the state of the machine and the technician. It's been 7 months and Jason, representative of the simpson company, tells me that they will not repair the water pump and blames me for excessive use (it was only tested once, never used at work) and it will not be repaired. I lost jobs, money in advertising, billboards.Update 2023, after having spent 7 months in the repair shop today they called me to return what was left of the washing machine. They did not return it and I had to pay the shipping costs for it. The guarantee did not take care of the bomb, from the guarantee they exposed that it was due to excessive use but it was never used when it exploded. It only remains to say that this machine is rubbish and it is throwing money at them, the company that manufactures them is not interested in the product once it is sold. But I thank Amazon because the heavy goods reps helped find a way out for my . Thanks Amazon! 👍🏻 ... show more
Reviewed in the United States on May 27, 2023 by German German
    • Durable and last
Good pressure washer!
Reviewed in the United States on March 2, 2026 by Haley

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