SIMPSON Cleaning MSH3125-S 3100 PSI Gas Pressure Washer Review

The Simpson Cleaning Company, part of the FNA Group are the producers of the Simpson Cleaning MSH3125-S 3100 PSI at 2.5 GPM gas pressure washer. Operating in the industry for the past 50 years, they are known for providing extra features like a standard set of 5 rather than 3 or 4 nozzles on the pressure washer. Meeting the needs of customers, they are versatile as the product itself.

The Simpson MSH3125-S is a compact, powerful machine for meeting all your outdoor cleaning needs, from deck, driveway and patio cleaning to restoring wood, removing graffiti and more. This engineering marvel can sustain optimal performance in even the most challenging environments.

Simpson Cleaning MSH3125-S
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A brainchild of company founder Jack Simpson, the first Simpson pressure washer developed in the 1960s to serve as equipment for paint contracting professionals. Light, versatile and multipurpose, the Simpson pressure washer has evolved over 5 decades of continuous improvement since then.

Synonymous with the top quality motors of all kinds, Honda has teamed up with top pressure washer brand Simpson to produce this one-of-a-kind cleaning machine. With the advent of the DIY era, the emphasis is on using technology you understand. The MegaShot Horizontal series is designed for professional and personal use, keeping this in mind. Providing top quality performance with minimum capital investment, this is a purchase that offers value for money. The Simpson MSH3125-S from the MegaShot Horizontal series is a 3100 PSI directly driven gas powered machine.

This pressure washer is a complete heavyweight which has solid dimensions. While most pressure washers are vertically oriented, this one is horizontal. One of the top pressure washers, the Simpson Horizontal series offers value in terms of:

  • Quality
  • Price
  • Power
  • Features

The 3100 PSI power MegaShot washer is no exception to others in the series and from DIY to professional, industrial use, it is light years ahead of the average gasoline powered pressure washer. To start with, a gas operated pressure washer is advanced when it comes to creating more pressure as against electric washers.

The power and pressure needs of the customer can be met in a budget friendly way, with this MegaShot series created for homes and shops. Lightweight, and compact, this pressure washer is a powerhouse when it comes to cleaning patios, desks, house sidings and outdoor furniture, or even preparing the exteriors of your home for a paint-job.

Simple to start, and easily operable in most difficult circumstances, this pressure washer has a PowerBoost technology providing high pressure nozzles for more impact and better cleaning performance.

Quick Specifications

Water Pressure

3100 PSI

Flow Rate

2.5 GPM


HONDA GC190, 187cc, 4-stroke, overhead cam/valve design.

Pump Type

OEM Technologies, Axial Cam Pump


10″ Premium Pneumatic Tires

Pump/Hose M22 Connector



25′ x 1/4″ MorFlex High Pressure Hose

Hose/Gun M22 Connector


Wand Type

M22 Connect Spray Wand, Quick Connect for spray nozzles

Engine Orientation



Welded Steel

Handle Style/Frame Tube

1.25″ Round Steel Tube


23.25 x 21 x 34.75 inches

Assembled Depth

34.75 inches

Hose Diameter

.25 inches

Assembled Height

23.25 inches

Hose Length (in.)

300 inches

Assembled Width

21 inches

Wheel Diameter

10 inches

Assembly Required


Nozzle Type


Compliance and Certification


Number of Tips Included




PSI Range

2600-3100 PSI

Connection Type

1/4 inches Universal Quick Connect Wand/Nozzle

Pressure Washer Power Type


Engine Displacement (cc)


Shipped Weight

72 pounds

Unit Weight

74 pounds

Item Weight

65 pounds


Chemical/detergent injection,Quick connect tips

Pump Type


Engine Type


Engine Make


Model Number



1-Year limited warranty, 2-Year Honda Engine, 90-Days gun hose lance Nozzles

Water Capability



Onboard cord storage,Wheels

Translucent Fuel Tank


Hose Material


Start Type

Recoil Start





Fuel Tank Capacity (gallons)


Product Link

Check this Product on Amazon →

Detailed Features

The features of the Simpson Cleaning MSH3125S 3100 PSI at 2.5 GPM are discussed in the table and subheadings here.

  • Resilient Honda GCV190 Engine

    The Simpson MS3125-S comes equipped with a Honda GCV190 engine which has a displacement value of 190cc. The engine has a 16 gauge, 1.25 inch steel welded tubular frame encasing it. Combining efficiency, power, durability and ease in operations, the Honda GC190 engine has a 4 stroke overhead cam/valve design.

    The premier Honda company has developed the engine for this pressure washer jointly with Simpson, to bring the best of power and performance, with the engine giving energy and the pump providing perfect pressure. This engine has tripartite components namely the choke control, starter grip and engine switch.

    Choke Control opens and closes the choke valve of the carburetor. Starter Grip is pulled for operating the recoil starter for cranking the engine.The Honda GC190 operates really smoothly and all you need to do is flip the switch. The machine can be disabled through the switch too.

    The Honda GVC190 also comes with an integrated safety lock to prevent sudden activation of the gun. For quiet, seamless functioning, nothing beats the power and control of the pressure washer engine made with quality components.

    Reliability and power come with the compact chamber for combustion, overhead cam or valve design for greater efficiency and uniblock construction for lowering fuel consumption. This engine is CARB and EPA emissions standard compliant.

  • PSI 3100 Pressure Pump

    This pressure washer’s pump produces a final pressure of 3100 PSI. With a durable pump design, the OEM hi-tech axial camp pump offers a unique PowerBoost technology for enhancing performance and lowering noise, heat and vibration. This extends the life of the pump and the engine. Pump offers high pressure nozzles, greater impact and cleaning performance.

    Maintenance-free, oil bath lubrication systems are in place while precision, well polished stainless steel pistons offer durability. A thermal relief system protects the pump from overheating. The pump distributes 2.50 GPM water flow, making it a winner among non-commercial cleaners. Stubborn stains, dirt, oil and grease are eliminated using this pressure washer.

  • MorFlex High Pressure Hose

    The MorFlex High pressure hose in the SIMPSON pressure washer offers utility and performance both. The detergent siphon offers a clever and efficient way to mix cleaning agents with liquid water. The 0.25 inch by 25 feet MorFlex pressure hose is extremely flexible, kink and abrasion proof and withstands marring.

    The quick connect 5 professional style nozzles make for easy cleaning. The siphon tube adds value to the detergent application. The Quick Connect hose’s diameter is one-fourth of an inch. The hose length is 25 feet and the maximum water flow rate is 2.5 GPM.Water pressure being PSI 3100, the power type, axial cam pump is superbly efficient.The poly braided hose is less likely to leak or have holes, and won’t leave scuff marks on cleaning surfaces. The hose pump and gun hose connection is 22 threaded connectors value.

  • Quick Connect Nozzle Tips

    A total of 5 different nozzles are attachable to the wand of the hose. A range of 40,25,15 and 0 degree nozzles and a soap applicator tip ensures all cleaning needs are met. The high pressure hose provides flexibility and is equipped with M22 connectors that are threaded. The hose is non kinking because it ensures the pressure moves in a forward direction so that the engine remains protected and the apparatus remains connected.

  • Spray Gun with Quick Connect Spray Wand

    The Spray Gun in the Simpson MS3125-S controls the water flow rate as well as the direction and pressure. The Quick Connect Spray Wand helps the user to make the change using the high pressure nozzles quickly. With columns of steel spray rods, the 5 stainless steel nozzles are easy to connect. A safety lockout system prevents accidental release.The spray gun comes with a pro-style Spray Wand. The nozzles ensure greater impact and better cleaning performance.

  • Tires

    The tires are 10 inch pneumatic tires for easy movement .

  • Voltage

    The hose has a cordless AC adjustable pressure regulation voltage.

  • Frame

    It has heavy gauge frame components and welded steel construction.

  • Additional Features

    These include the convenient on-board accessory storage for spray gun, wand, high pressure hose and nozzles. Other parts include the handle, frame, pump out and inlet, the nozzles and nozzle holder.

What Comes with SIMPSON MS3125-S

  • Pressure Washer

    This is the main body of the MS3125-S comprising its engine and components.

  • Hose

    This is a 25 inch hose that connects the nozzle to the outlet. The pump connects the hose through an M22 connector.

  • Wand

    This is an M22 Quick Connect Spray Wand for spray nozzles.

  • Gun

    This ejects the pressure with the nozzles attached to it.

  • 5 Quick Connect Nozzle Tips

    This comprises Quick Connect nozzle tips 1–5 which are color coded for accuracy and difference in pressure.

  • Detergent Siphon Tube with Filter

    This component ensures that the detergent is not filled directly into the engine and that it is filled into the jet spray to access hard to reach areas.

  • Engine Oil

    Standard grade engine oil for this pressure washer is also supplied.

  • Owner Guide & Owner’s Manual

    The owner’s guide and manual covers everything from the specifications to the directions and safety instructions.

Detailed Specifications

The specifications of the Simpson Cleaning MSH3125-S 3100 PSI at 2.5 GPM pressure washer are presented below:

  • Water Pressure and Flow Rate

    The water pressure of this pressure washer ranges from 2600 to 3100 PSI. The water flow rate is at 2.5 GPM.

  • Engine and Pump Type

    The Simpson MS3125-S has a Honda GC190, 187cc 4 stroke overhead cam valve design and a powerful, sturdy capability to power performance for as long as 85 hours, according to some reports. The OEM Technologies Axial Cam Pump is also a key feature of the pressure washer components.

  • M22 Connector

    The Pump and Hose as well as the Hose And Gun are connected by a M22 threaded connector.

  • Wand and Spray Gun

    The M22 Connect Spray Wand has a Quick Connect feature for connecting the nozzles at various angles ranging from 0 to 40 degrees.

  • Frame and Handle Style

    Made of welded steel with horizontal orientation and 1.25 inch round steel tube, this pressure washer comes in user-friendly dimensions of 23.25 x 21 x 37.45 inches.


The Honda engine provides 3100 PSI of pressure washing that is efficient as opposed to the competition. It commences with just one pull at most of the times and for the price it is given, it offers the best value. Here are the pros of this cleaning machine.

  • Easy Replaceability and Durability

    The nozzles are easily replaceable for differing applications. The construction and build quality of the product makes this a long lasting pressure washer.

  • Portability and Mobility

    The washer is easy to move with pneumatic tires and it works with efficiency to clean hard to reach surfaces on account of its 25 inch hose.

  • Strength

    The Simpson MSH3125-S is useful for cleaning, thanks to the powerful Honda CG190 engine and the Axial Cam Pump. Honda is known for engines used across the world. The Axial Cam Pump offers a 2.5 GPM and 3100 PSI water pressure without hesitation.

  • Excellent Fuel Tank

    The device has a large fuel tank weighing 1.9 quarts. The tank of fuel will clean the entire house more than once. The 6 gauge steel tube frame and the 12 gauge engine plate makes the device body strong.

    The convenient and integrated spray gun, a 25 foot water hose and a wand hanger onboard make cleaning easier.

  • Convenience in Size

    The device around 23.25 x 21 x 34.75 inches in dimension is heavier than electric pressure washers, but lighter than gasoline run pressure washers. This 38.56 kg weight makes it easier to move around with too.

  • Warranty

    2 full years of warranty on the engine, 1 year on the pump and 90 on the spray warranty items makes it extremely easy for users to get the maintenance and replacement services (if any) they need.

  • Heavyweight Powerhouse

    Built with quality components to provide high durability, this 3100 PSI pressure washer is robust and durable with maintenance free technology and lasting value. Pro-style steel spray with multiple Quick Connect nozzle tips and onboard accessory storage makes it excellent for use.

  • Safety Factor

    The safety lock prevents the gun from being activated by accident. The Honda engine gives the cleaning power needed. Extremely user friendly, it is moveable, easy and safe to clean. It provides comfort and control.

  • Wide Application

    The premium quality gas pressure washer can be used for cleaning up home exteriors,sidewalks, decks, outdoor furniture, patio, paint prep, fences, vehicles, cars, boats, pools, driveways and sidewalks. The pressure washers are tested in the factory and contain minimal residual fuel or odor. This is a versatile pressure washer which is ruggedly built, with a safety lockout and ergonomic spray gun.

  • Hassle-Free Maintenance

    Equipped with a zero- maintenance pump, this delivers around 2.5 gallons per minute. This MegaShot washer offers cleaning power that is unparalleled and no oil for operating. Air cooled, 4 stroke, 187 cc engine with a compact design makes this easy to use and maintain. As there is a separate detergent siphon hose, the pressure washer’s engine does not have to be cleaned. Color coded nozzle permits wide variety of applications from hard surface spot cleaning to safe cleaning of delicate surfaces. Compact, lightweight and a powerhouse when it comes to quality, this is the best cleaning equipment for any surface.


There are a few disadvantages associated with the MegaShot model. Read on to know more.

  • No Detergent TankThe device lacks a detergent tank. This makes it inconvenient for those users looking to use the tank.
  • Low Durability of the Pump, Fragile Hose

    There is a pump durability issue, in comparison to the rest of the unit and the hose can be fragile on account of its length.

  • For External Use Only

    This pressure washer can only be used outside and is harmful if used within indoor settings.

  • Oily Residue, Gas Discharge

    The pressure washer does not have the benefits an electric washer would, such as lack of oily residue or gas discharge

Frequently Asked Questions (FAQ)

Those interested in the Simpson MS3125-S may have queries which need to be resolved. Existing customers may also have concerns. This FAQ attempts to answer them.

Q: What Makes the Simpson Pressure Washer Different?

The unique benefit of a Simpson pressure washer is that these are designed to inject detergents into the high pressure stream. Most pressure washers offering a detergent option require wands to be sprayed at a low pressure setting of a spray wand at half the maximum PSI. A 3200 PSI would distribute detergent at 1600 PSI. But with the Simpson pressure washer, the full 3100 PSI capacity is available.

Q: What More Options Are Available in This Model?

Additional options are available for wet sandblasting and thermal rubber hoses for all season pressure washing.

Q: How Does the Simpson MS3125-S MegaShot Model Work?

Once the unique combinations have been selected, the pressure washer can be simply used. The water source is connected to it for filling up the fuel reservoir with gasoline or plugging it into an outlet. Hold the trigger and let the water come into the machine for a minute or more. The Simpson pressure washer is therefore used for cleaning in ways that are efficient and filled with utility.

Q: Who Is the Manufacturer?

The manufacturer is the Simpson Cleaning System company created by Jack and Betty Simpson in the early 1960s. All products of this company were handmade till 1985. Now, cutting-edge technologies and processes are used. The FNA Group (now parent company of Simpson Cleaning Company) manufactures pressure washers, pumps, hoses and accessories. The focus is functional innovation and they provide a wide range of machines and accessories.

Q: Where Is the FNA Group Based?

They are based in Wisconsin, US.

Q: What Can the Simpson MSH3125-S MegaShot 3100 Be Used For?

This gas washer is even more powerful than an electric pressure washer. With 3100 PSI and 2.5 GPM the cleaning is carried out with ease and efficiency. Sheer power means nothing will be damaged and the MegaShot comes with different nozzle strengths. The switch from the lower to the higher pressure is perfect for cleaning surfaces from the patio to the furniture, grill, driveway and house siding.

Q: What Are the Advantages of Using a Simpson MSH3125-S MegaShot 3100?

It has a 190cc Honda engine that is reliable as well as durable. The benefit of this Honda engine is that it is easy to start. The 10 inch premium pneumatic tires make movement simple. The MSH3125-S has a compact design and the horizontal orientation makes it easy to handle this. This gas washer has a 25 feet hose which is highly flexible so difficult to reach areas can be cleaned.

Q: What Are the Safety Features?

This is a safe pressure washer for use and there is no compromise on performance. Another benefit of the Simpson MegaShot is an axial cam pump known for being durable in the industry.

Q: What Is the PowerBoost Technology?

Patented PowerBoost technology has high pressure which benefits the cleaning process. The downstream injection involves the use of a siphon hose. As the detergent is not placed in the onboard tank, cleaning the same is not needed. Moreover, the detergent will not damage the pump. A reason it benefits the user is that the gas pressure washer can be used for long hours without any strain.

Q: What Does the MegaShot Run On?

The MegaShot is a high pressure washer running on an engine gasoline powered and can be used to remove a range of dirt and mould from different surfaces such as homes, offices, fences, floors and vehicles and hard to reach areas. The 25 feet long hose with its reach and flexibility makes cleaning the lawn an easy task.

Q: What Are the Safety Precautions for This Pressure Washer?

This device is easy to use provided the safety instructions are followed. The Simpson MSH3125-S is not designed to be used inside the closed space. Combustion that takes place in the engine releases a byproduct namely noxious carbon monoxide. So this odorless and colorless gas can prove fatal if the pressure washer is used indoors. The amount of fresh air supplied by outdoor vents or windows cannot counter the effects of CO. Exhaust from the pressure can get into the home through vents.

Video Guide: How to Use a Simpson MS3125-S Pressure Washer

The user can learn more about the Simpson MS3125-S at the video link below:


This is a pressure washer which is compact, easy to move and delivers value in terms of its features such as the handle bar, nozzle etc. It is up to any cleaning task at home or shop settings, efficient and simple to use, maneuverable and durable. The water flow of this pressure washer is perfect for all cleaning jobs. From a bike on a dirt trail to an SUV or houseboat, the pressure washer can be used across a wide range of cleaning requirements.

The nozzle’s variability makes it easy to use this pressure washer throughout the year for different cleaning needs. Different nozzle angles make it possible to reach enclosed surfaces too. Efficient cleaning, quality components and a rugged, durable steel frame makes this an awesome pressure washer. With a warranty that is offering maximal coverage, buying this pressure washer is the best purchase decision to make. Cleaning will seem less of a chore and this is one multipurpose gas pressure washer that takes the work out of maintenance as well.

Review Date
Reviewed Item
SIMPSON Cleaning MSH3125-S
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Hi, I'm James. The Chief Editor at I worked in Pressure Washer industry for a few years, and I thought to share my knowledge about pressure washer on our blog with my team.

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