Aluminum Series

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.

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.

When it is working, it’s so powerful and smooth. Design and built seems and feels high end and durable, however, it is VERY HARD to start. If the first full doesn’t start, no chance to start at second attempt. I owned gas pressure washer for almost 30 years, none of previous ones does that. It is way more pickier than my previous Excel. The Excel lasts 15 years for me. First, it is picky about fresh gas, it refused to start while brand new maybe just because the gas was two months old, now again, it won't start because the gas was almost two months again. My previous Excel can use gas more than 6 months old, Simpson engine is a princess--high maintenance picky machine. Second, the pressure built up so fast, if the first attempt wasn't successful, no way to start at the second. Even my neighbor who got a cheaper model of Simpson said this one is TIGHT. I'm so SCARED of starting it every time, needs a lot of pulls and luck. Excel only needs about 1-2 seconds of release pressure , this Simpson really needs 30 seconds to try my second luck. To start the machine is a TWO man job, one has to release the trigger on the other end constantly!! Third, even if I'm lucky to start it, it coughs/farts often and I have to be very careful to move the engine from choke to normal SLOWLY, otherwise it stops. Fourth, it gives farts loud several times when switched to off position. None of my previous ones did that, not once. Now I have to get used to the random noise after spending $800! Ordered one electric pressure washer last night, I'm done with the gas one especially with NO HELP from the seller...weird from day 1 Tech support is NOT responsive at all! My question never received answer.

Wanted to wait for some time to pass before making a real a review on my pressure washer. Purchased in sep 2021 and it’s now Jan 2025, so I have used it for 3 warm seasons since I only use it during the warmer months in PA. Did A LOT of researching before pulling the trigger on getting this unit. Some might think it’s expensive for someone who may only use it for home use and not commercial, but it’s perfect and reliable! I wanted something that would be versatile and beneficial with all projects. I always do the recommended maintenance and when storing for winter I winterize it. Maintenance is key for anything and I believe taking care of this will make it last for years of use. Main selling points for me and things I like: - CAT AAA pump, Honda engine, warranty, GPM, heavy duty but “light weight” frame/wheels, and being able to not worry about damaging the pressure washer if you release the handle while it’s running (not something I do often but know that’s a big no no when it comes to other pressure washers that don’t have the feature to allow this. High PSI and also the ability to lower the rpm’s to use it for lighter duty tasks. My complaints over the years: - The rubber feet that come with this unit are garbage, plan on replacing them with bigger and better feet because these ones will not last and the pressure washer will walk around on you. - I wish there was a better design for changing the oil, it’s a pain in the butt but with the right set up it wouldn’t be a big deal - It a little awkward when wheeling it around but it’s not a big deal and is only heavy if you are picking it up by yourself to go up stairs or things like that. Overall I would highly recommend this and would purchase again! Hope this helps you :)

This was originally going to be a four-star review but...(read on)... I bought this to replace an old Husky electric pressure washer I found on clearance and the big orange store about fifteen years ago. While it still worked, it wasn't very powerful and not much good for anything other than washing the car. I needed something to clean my travertine pool deck, pool waterline, and paver driveway and walks. I also wanted something I knew would be reliable so I wanted a Honda GX engine and CAT pump. This unit checked all of the boxes. Having used it three times so far, I can say I'm not at all disappointed in the performance. It started right up, ran flawlessly, and cleaned everything it needed to quite easily. I did add an inductive hour meter to it before I tarted it up for the first time so I could track the usage for proper maintenance. A few tips...buy a short gun and a long hose. Both will come in handy. It comes with a 25 foot hose so I bought a 50 foot hose (same hose from Simpson) and can connect them for 75 feet of hose. If you have a larger area to clean, you'll appreciate not having to move the machine much. Also, get a surface cleaner. It will cut your work time an a horizontal surface tremendously. I bought a 14" one and I guess a bigger one would have make things a bit faster, but the one I bought was a good compromise between cost and performance. So, why was this going to be a four-star review? Well, the few times I used it, one of the wheels kept falling off as the "E" clip would constantly vibrate off the axel. I kept putting it back on, believing I had it properly seated and it kept falling off. Frustrated, I called the customer service number and they are sending a new "E" clip. While this may solve the problem, I can't really be sure it's not a bad axel that the clip won't properly seat in. So, I emailed Simpson through the "Contact Us" link on the website and within a couple of hours had a response that they are sending me a new axel and clip. Things have issues from time to time but how issues are handled matters. The quick answer to my inquiry and no questions asked (other than my name, address, and unit serial number and purchase date) response was enough for me to be satisfied and provide the five-star review.

Researched a new pressure washer for weeks. I looked at all sorts of online suppliers and Amazon had exactly the model with the engine I was looking at that matched my requirements. Delivery was fast, the pressure washer was in perfect condition and once I got the oil into the engine and gassed it up, the engine started on the first pull. The engine is shipped without oil but oil is included. The hydraulic pump has oil in it but be SURE to remove the small black plug from the center of the red hydraulic pump cover or you can damage the pump. I did have one issue on arrival that has been reported by other Amazon customers. See the photo of the wheel with the arrow pointing at the retainer clip. That clip came off almost instantly. I removed the axle and both wheels and used a triangular file to cut the notch in the axle a bit deeper on both sides to hold the retainer clip. Sloppy manufacturing on the part of Simpson. I’ve used a very similar but smaller version of this Simpson pressure washer for decades. Honda engine is the only way to go and the Cat pump has seal rebuild kits. The 5 pressure tips included cover most situations and pay attention to using the right tip for the right job. The 3400 psi model is ideal for most homeowner purposes including siding, concrete, and patio cleanup. NEVER point the water stream at skin, other people or animals. A 3400 psi water jet up close can cause severe tissue and damage skin in an instant. Wear work shoes with safety toes and eye protection. As a long time owner of machine exactly like this one there are a few things owners need to do to ensure quick starts and trouble free service. I read many low star reviews focused on hard starting. It’s not the machine, it’s the owner and their failure to follow some simple maintenance rules. This is key - ALWAYS run the fuel out of the carb when you’re done even if the machine will only sit for a few days. Use ethanol free gas with fuel stabilizer. Failure to use stabilizer and run the carb dry will cause 90% of hard starting problems. Change the engine oil and the hydraulic pump oil more often than required and use the proper oils. Check the air filter and the fluids regularly. I really like Simpson machines with Honda engines. I’ve had tremendous longevity and cleaning outcomes from these machines, and I highly recommend them. I deducted 1 star for 3 reasons. The first reason is the axle issue mentioned above where the retainer clip pops off that I fixed. Second is that the handle is too short if you are 6 feet or taller like me - it's an ankle biter when I pull it around. Finally, it needs flat free wheels, pneumatic wheels are annoying. That's it - great machine with some shortcomings. Hope this helps!

So far so good. Easy to assemble. Started right up. Hope it last for years

This washer is amazing. I had another washer that was good for ten fifteen years. But this thing i'm just so glad about it.And it was a little more money.I want than I wanted to spend, but and after I use it.It's got so much power.And so much gallons per minute, and the engine is just phenomenal. I've had honda engines before and liked them.But this thing can sit for a month and then one pole, and it fires right up.I love it. I would highly recommend this, and I don't do very many reviews, but on this one.I will just because it is so good.