SIMPSON MSH3125-S Review | 3100 PSI Pressure Washer

The SIMPSON MSH3125-S is one of best pressure washers for the money. A wonderful balance of quality, features, power and price. Overall, this 3100 PSI power washer should be at the top of your list. To learn why, just keep reading and you can make up your own mind.

We also cover the following Simpson models: SIMPSON PS4240H (4200 PSI), SIMPSON PS3835 (3800 PSI), SIMPSON PS3228-S (3200 PSI).

Say Goodbye to Dirt, Filth, Grime & Scaling Paint

Dust and grime are the bane of our existence. The need to keep our surroundings clean is real and yet it isn’t always practically possible — especially when it comes to keeping our outside environment clean. Nature has its way of messing everything up.

The SIMPSON brand has become popular because of their commitment to quality and reliability in all of their pressure washers — which is all they manufacture, making them experts in their industry. The MSH3125-S is one of the most popular pressure washers available today. Customer satisfaction is very high — which is a true indicator of the quality of a product measured over time.

SIMPSON MSH3125-S | 3100 PSI Pressure Washer

The SIMPSON Company

Simpson is a vertically integrated company. This concept means that all the parts and accessories that are required for production of their machines are manufactured by the company itself. The advantage of this system is quality control. The Simpson is able to monitor the quality of each and every part and accessory used.

The company was started by Jack Simpson in the early 1960’s. He found his big break while he was constructing pressure washers for painters. He used a simple idea. He used an engine from a gasoline based peanut harvester and placed it on a portable cart. It was from that point of time in history that production of pressure washers in Simpson began in full swing!

Needless to say, the Simpsons continued their fabulous work. Every hurdle has been turned into a stepping stone for their policy revolves heavily on learning from their mistakes. This is one company that consistently keeps making better and better products!

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SIMPSON Megashot Horizontal Series

The ‘Do-it-yourself’ era is upon us and most of us like to incorporate this trend in all aspects of our lives. The Megashot Horizontal series is designed with this fad in mind. This series is designed for both home as well as shop use. It provides high quality performance with very minimal investment.

The Megashot Horizontal series focuses on a few features that make these models perfect for ‘Do-it-yourself’ projects. One of the well-known models in this series is the Simpson MSH3125-S. Let’s take a look at a few of the features that make the Megashot Horizontal series unique.

Engine Features | Simpson MSH3125-S

• Simple to use: Simplicity is the key to all Do-it-yourself projects. It means less accidents and better results. The Megashot Horizontal series is easy to use and is perfect for cleaning areas like decks, home exteriors, patios and even house sidings.

• Compact and light weight design: Most Do-it-yourself projects are a one man/woman job. A compact design means easier handling. Light weight designs means that the equipment is easy to transport. The Megashot Horizontal series has been designed in a way that a single person can easily transport the pressure washer.

• The engines: The pressure washers use engines that are designed by Honda, Simpson and Kohler. These engines are well known for their high quality components. They are easy to start and give optimum performance.

• Patented PowerBoost technology: This technology helps provide a much higher pressure at the nozzle. This increase in pressure translates to a greater impact and a better cleaning performance.

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Simpson MSH3125-S | 3100 PSI Pressure Washer

The Simpson MSH3125-S is a 3100 PSI direct drive gas powered pressure washer belongs to Megashot horizontal series. There are some specialties of this machine that adds a draw to almost all potential buyers.

Features:

• HONDA GC190 Engine. 187cc, 4-stroke, overhead cam/valve design.
• 3100 PSI / 2.5 GSM (Flow Rate).
• Maintenance-free OEM Technologies Axial Cam Pump with POWERBOOST Technology for Increased Performance.
• 25′ x 1/4″ MorFlex high pressure hose is kink and abrasion resistant, provides flexibility, and is equipped with M22 connectors.
• Heavy Gauge Frame Components, welded Steel Construction and 10” Premium pneumatic tires.
• Pro-style spray wand with 5 quick connect nozzle tips : – 0°, 15°, 25°, 40° and soap nozzle.
• Professional spray gun with safety lock-out.
• Convenient on-board accessory storage for spray gun/wand, high pressure hose, and nozzles.
• Downstream Detergent Injection System.

The Specifications

The device comes with a Honda GC190 engine which is what helps produce the 3100 PSI pressure. That however isn’t the only part of the machine that is interesting. The Simpson MSH3125-S also comes with maintenance free OM technologies like the Axial Cam pump. The Powerboost technology also helps increase the performance of the device.

The hose that is used is a 25 inch by ¼ inch MorFlex high pressure hose. The hose is kink and abrasion resistant. This feature is very important because if the hose kinks the pressure will be exerted in backward direction. The end result can be that the hose will get disconnected or it may adversely affect the engine. If it gets disconnected, the force of the water can affect people who are standing around it. The hose also provides flexibility. It also comes equipped with M22 connectors.

The Heavy Gauge Frame components of the Simpson MSH3125-S along with the welded steel construction and the 10 inch pneumatic tires give the machine a sturdy and durable body. This means that the maintenance of this product is way less than what you would have originally expected it to be.

The spray gun has its own set of specifications.  The Simpson MSH3125-S comes with a pro-style spray wand. It also has five quick connect nozzle tips. These nozzle tips come as 0^o, 15^o, 25^o and 40⁰. The last and final nozzle is labeled ‘soap’. This nozzle is used as a soap applicator. The professional spray gun of the Simpson MSH3125-S has a safety lockout too!

The Dimensions

The measurements of any machine or product are important because they give you an idea of how big the device is. Let’s take a look at the dimensions of the Simpson MSH3125-S.

Specs:

• Water Pressure:  3100 PSI
• Flow Rate:  2.5 GPM
• Engine : HONDA GC190 — 187cc, 4-stroke, overhead cam/valve design.
• Pump Type:  OEM Technologies — Axial Cam Pump
• Wheels : 10″ Premium Pneumatic Tires
• Pump/Hose M22 Connector : Yes
• Hose: 25′ x 1/4″ MorFlex High Pressure Hose
• Hose/Gun M22 Connector :     Yes
• Wand Type: M22 Connect Spray Wand with Quick Connect for spray nozzles
• Engine Orientation: Horizontal
• Frame: Welded Steel
• Frame Tube/Handle Style : 1.25″ Round Steel Tube
• Unit Length : 34.75″ (L) x 21″ (W) x 23.25″ (H)
• Unit Weight :  65 lbs

Documents for the Simpson MSH3125-S Pressure Washer:

• ✓ View or download the MANUAL.
• ✓ View or download the PARTS LIST.
• ✓ View or download the SPEC SHEET.
• ✓ View or download the ENGINE MANUAL (HONDA GC190).

Learn more about the MSH3125-S pressure washer on Amazon.

Parts Of The Simpson MSH3125-S

Understanding a machine largely depends on knowing what the device is comprised of. The Simpson MSH3125-S has a handful of major parts that any prospector buyer/owner needs to know about.

• The Pressure Pump: This part of the Simpson MSH3125-S increases the pressure of the water flowing through the device. The final pressure that this pump produces is 3100 PSI.
• The Hose: Carrying the water from to the nozzle requires a really good hose. The hose that is used is a MorFlex High Pressure hose. The dimensions of which are given in the table above.
• The Engine: The high pressure pump requires a good enough engine to drive it. The Simpson MSH3125-S is a Honda GC190 engine.
• The Spray Gun: This part of the Simpson MSH3125-S helps to control the water flow rate. It also helps control the direction and the pressure.
• The Quick Connect Spray Wand: This is designed to help the user change the high pressure nozzles quickly.
• The Detergent Siphon Hose: The device also has a method of mixing cleaning agents with the water. This is done by using the Detergent Siphon hose.
• Other parts include the handle, the frame, the pump outlet, the pump inlet, quick connect nozzles and the nozzle holder.

Included Nozzles | Simpson MSH3125-S

Engine Overview | Honda GC190

As stated before, the Simpson MSH3125-S functions using a Honda GC190 engine. This engine has three parts that you need to be aware of. They are the choke control, the starter grip and the engine switch.

Engine Switch: The Honda GC190 engine starts quickly. This means that all you have to do is flip the switch and the machine is turned on. The Simpson MSH3125-S can be disabled at the turn of the switch too!

Choke Control: This is used to open and close the carburetor choke valve.

Starter Grip: The starter grip is pulled in order to operate the recoil starter to the crank engine.

Features (Honda GC190 engine):

• Fuel Efficient, High Output Operation
  • Compact combustion chamber, overhead cam design, and uniblock construction reduce fuel consumption
  • Powerful torque across a wide RPM range helps reduce engine speed drop from sudden load increases.
• Compact and Lightweight
  • The lightest engines in their class
  • The world’s first general purpose engine internal timing belt
  • Tough resin overhead cam for durability and quietness
  • Uni-block construction
• Quiet, Smooth Performance
  • Internal timing belt provides quiet operation
  • Valvetrain and gear noise is minimized
  • Precision engineered and machined components result in lower vibration
• Proven Reliability
  • Dua-Lube System provides superior engine lubrication
  • Simple construction reduces many potential maintenance needs
  • High quality materials, fit, and finish
  • Single element air filter
• Easy to Use and Maintain
  • Easy access oil drain and fill
  • Easily accessible spark plug
  • Proven lifetime timing belt design
• Easy Starting
  • Horizontal cross-flow intake port to smooth the flow of fuel
  • Automatic mechanical decompression
• Emissions Compliant
  • CARB and EPA certified
  • No catalyst necessary
  • Built in charcoal canister in gas cap

Visit the Honda site to learn more about the engine.

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Safety Instructions | SIMPSON MSH3125-S

Safety should always be the focus of your attention when it comes to any form of mechanical device. This is even more important when you use power tools. The Simpson MSH3125 is an easy device to operate but use it the wrong way and it can be fatal.

Carbon Monoxide & Indoor Use

The Simpson MSH3125-S is not designed to be used inside any closed space. This is because the combustion that occurs in the engine releases a byproduct called Carbon dioxide. This gas is noxious. The problem with this poisonous gas is that it is odorless and colorless. This means that you will have no warning how high the Carbon Monoxide levels are and this could prove to be fatal.

Remember that using a fan does not help. Open doors and windows also do not help remove the noxious gas. This is because the amount of fresh air supplied by doors and windows is not enough to counter the harmful effects that Carbon Monoxide causes.

NEST CO + Smoke Alarm | A Good Investment for Your Home

Another important safety precaution that must be taken is related to the placement of the Simpson MSH3125-S. The machine should be placed outdoors and the place should be away from open windows and doors. This is because the wind could drive the Carbon Monoxide inside the house and can cause poisoning of anyone who is inside.

Keep in mind that the signs of Carbon Monoxide poisoning include dizziness, headache, vomiting, chest pain and even confusion. If you experience any of these symptoms, switch off the machine and visit your doctor immediately!

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Other SIMPSON Pressure Washers

All three of the SIMPSON models below have these common features:

• AAA industrial triplex plunger pump with PowerBoost technology which provides higher pressure at the nozzle.
• OHV commercial series engine with Oil Alert.
  
• Honda 4-Stroke engine.
• 50′ x 3/8″ Non-Marring Steel-braided Hose with Quick Connectors.
• Welded steel frame, steel engine plate, solid steel axle and 13″ pneumatic tires.
• Pro-style spray wand with 5 quick connect nozzle tips : – 0°, 15°, 25°, 40°, and soap applicator nozzle.
• Professional spray gun with safety lock-out.
• Convenient on-board accessory storage for spray gun/wand, high pressure hose, and nozzles.
• Down Stream Injection System.
• Accessory on-board storage.

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SIMPSON PS4240H | 4200 PSI Pressure Washer

Engine: HONDA GX390 (389 cc/11.7 HP) Commercial Series Engine with Oil Alert.

• AAA industrial triplex plunger pump with PowerBoost technology which enables higher pressure at the nozzle.
• 50′ x 3/8″ Non-Marring Hose with Quick Connectors.
• Welded steel frame, steel engine plate, solid steel axle and 13″ pneumatic tires.

Specs:

• 389 cc. / 11.7 HP / Air-cooled 4-stroke OHV
• Water Pressure : 4200 PSI
• Flow Rate : 4.0 GPM
• Engine Manufacturer: HONDA GX390 Commercial Series OHV Engine with Oil Alert
• Pump Type: AAA Industrial Triplex Plunger Pump
• Wheels : 13″ Premium Pneumatic Tires
• Hose : 50′ x 3/8″ MONSTER Hose with Quick Connectors
• Wand Type : Quick Connect Spray Wand
• Size : 37″ (L) x 23″ (W) x 28″ (H)
• Weight : 141 lbs

Documents for the Simpson PS4240H:

• ✓ View or download the MANUAL.
• ✓ View or download the PARTS LIST.
• ✓ View or download the SPEC SHEET.
• ✓ View or download the ENGINE MANUAL (HONDA GX390).

Engine Specs (HONDA GX390):

• Engine Type : Air-cooled 4-stroke OHV
• Displacement : 389 cm3 (389 cc)
• Net Power Output : 11.7 HP (8.7 kW) @ 3,600 rpm
• Net Torque : 19.5 lb-ft (26.4 Nm) @ 2,500 rpm
• Compression Ratio : 8.2:1
• Fuel Tank Capacity : 6.4 U.S. qts (6.1 liters)
• Fuel : Unleaded 86 octane or higher
• Dry Weight : 69 lb (31.5 kg)

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SIMPSON PS3835 Powershot | 3800 PSI Pressure Washer

AAA industrial triplex plunger pump with PowerBoost technology.

Engine: Honda GX270 (270 cc/8.5 HP) Commercial Series Engine with Oil Alert.

• AAA industrial triplex plunger pump with PowerBoost technology which enables higher pressure at the nozzle.
• 50′ x 3/8″ Non-Marring Hose with Quick Connectors.
• Welded steel frame, steel engine plate, solid steel axle and 13″ pneumatic tires.

Specs (SIMPSON PS3835):

• 270 cc. / 8.5 HP / Air-cooled 4-stroke OHV
• Water Pressure : 3800 PSI
• Flow Rate : 3.5 GPM
• Engine Manufacturer : HONDA GX270 Commercial Series OHV Engine with Oil Alert
• Pump Type : AAA industrial triplex plunger pump with ceramic coated pistons and PowerBoost
• Wheels : 13″ Premium Pneumatic Tires
• Hose : 50′ x 3/8″ Monster Hose with Quick Connectors
• Wand Type : Steel Quick Connect Spray Wand
• Size: 32″ (L) x 23″ (W) x 28″ (H)
• Unit Weight : 123 lbs.

Documents for the Simpson PS3835:

• ✓ View or download the MANUAL.
• ✓ View or download the PARTS LIST.
• ✓ View or download the SPEC SHEET.
• ✓ View or download the ENGINE MANUAL (Honda GX270).

Engine Specs (Honda GX270):

• Engine Type : Air-cooled 4-stroke OHV
• Net Power Output : 8.5 HP (6.3 kW) @ 3,600 rpm
• Net Torque : 14.1 lb-ft (19.1 Nm) @ 2,500 rpm
• Compression Ratio : 8.5:1
• Fuel Tank Capacity : 5.6 U.S. qts (5.3 liters)
• Fuel : Unleaded 86 octane or higher
• Dry Weight : 55 lb (25 kg)

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SIMPSON PS3228-S | 3200 PSI Pressure Washer

Engine: HONDA GX200 (196 cc/5.5 HP) OHV commercial series engine with Oil Alert.

• AAA industrial triplex plunger pump with PowerBoost technology gives you higher pressure at the nozzle increasing your cleaning speed.
• 25’ x 5/16″ MorFlex high pressure hose is highly flexible, non-marring, kink and abrasion resistant. Equipped with M22 connectors.
• Welded steel frame, steel engine plate, solid steel axle and 10″ pneumatic tires.

Specs (PS3228-S):

• 196 cc / 5.5 hp Honda GX200 4-stroke engine. Overhead valve design.
• Water Pressure : 3200 PSI
• Flow Rate : 2.8 GPM
• Engine Manufacturer : HONDA GX200 Commercial Series OHV Engine with Oil Alert
• Pump Type : AAA Industrial Triplex Plunger Pump
• Wheels : 10″ Premium Pneumatic Tires
• Hose : 25’ x 5/16” MorFlex high pressure hose
• Unit Size: 34 (L) x 20″ (W) x 25″ (H)
• Unit Weight : 85 lbs.

Made From High Quality Components

Learn more on Amazon.

Documents for the Simpson PS3228-S:

• ✓ View or download the MANUAL.
• ✓ View or download the PARTS LIST.
• ✓ View or download the SPEC SHEET.
• ✓ View or download the ENGINE MANUAL (HONDA GX200).

Engine Specs (Honda GX270):

• Engine Type  :  Air-cooled 4-stroke OHV
• Net Power Output  :   5.5 HP (4.1 kW) @ 3,600 rpm
• Net Torque  : 9.1 lb-ft (12.4 Nm) @ 2,500 rpm
• Fuel Tank Capacity : 3.3 U.S. qts (3.1 liters)
• Fuel : Unleaded 86 octane or higher
• Compression Ratio :  8.5:1

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Fire And Safety

*This applies to all powerful pressure washers. Please read as it’s very important to know.

Since the Simpson MSH3125-S is a gas powered engine, it functions by using internal combustion. Like all machines that use internal combustion, the Simpson MSH3125-S has a high chance of producing sparks. These sparks can cause a fire hazard. This is why the Simpson MSH3125-S should be equipped with a spark arrestor (or spark arrester). You will find that this is especially important when there is flammable material (like agricultural crops, forests etc) around. In case, the device does not have a spark arrestor, make sure that you get one installed immediately. Some states require the mandatory use of a spark arrestor. California is one of them.

Fires may occur when liquid gasoline (which has been spilled) or its vapors come in contact with cigarette sparks, electrical wiring etc. The best way to prevent such a situation is by switching off the Simpson MSH3125-S and allowing it to cool. Fill the tank with care so that you avoid any unnecessary gasoline spillage. Another important safety instruction is do not smoke (or let anyone else smoke) when you are using the machine.

The level of fuel in the fuel tank also plays a very important role in fire safety. The maximum amount of fuel in the fuel tank should be ½ inch below the filler neck. This is because the heat causes the fuel in the tank to expand. This could result in either a spillage or an explosion.

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Video | Consumer Reports Pressure Washer Buying Guide

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Fluid Injections and Lacerations

The Simpson MSH3125-S produces 3100 PSI of pressure. This pressure is immense when it is applied on any surface. Point it at skin and it will penetrate through it. The force is enough to cause an amputation or a really serious injury. This is why it is important to treat all kinds of fluid injections and lacerations immediately.

To avoid such injuries, it is important to check the high pressure hose regularly. Your check should involve a search for areas in the hose that look worn out or damaged. Look for signs of pin-hole leaks and cracks. If you do find a leak in the hose ensure that you do not try to cover the area with your hand. Since the pressure of the water is high (3100 PSI), the water will penetrate through the skin and cause a fluid injection injury.

The nozzle should never be pointed at anyone. Do not even attempt to place your hands in front of the nozzle. Remember that even though the injury may look small from the outside, the internal injuries may be devastating.

The spray can also cause objects to dislodge and form projectiles. These projectiles can cause a lot of harm if they hit someone who is standing in the way. To ensure that this does not happen, secure the trigger lock when you aren’t using the Simpson MSH3125-S. This will ensure that accidental operation does not occur.

Purchasing a high pressure washer has a lot of benefits. It certainly reduces the amount of work that a person has to do. The Simpson MSH3125-S is a very good machine and it has consistently delivered good results. Using a high pressure tool however requires skill and caution. While the company does advertise this device as a ‘Do-it-yourself’ model, ensure that you read the manual carefully. Know the safety precautions that you must take before you experiment with it. Remember that safety must always be your primary concern!

Visit the SIMPSON site to learn more.

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Additional Resources:

• How to pressure wash you deck