Consumer pressure washers are built so the pump is not worth replacing. When it goes, the machine goes. A build using a serviceable pump package flips that: the pump is rebuildable, and when the engine eventually dies you keep the pump.

The RMW22G24-EZ-PKG is built for exactly that job: 2.2 GPM at 2,400 PSI, on a 7/8 in hollow shaft, in a box with everything you need to bolt it down and run it.

What ships with the RMW22G24-EZ-PKG

• RMW22G24-EZ axial radial pump
• Pressure regulator and unloader assembly
• Thermal relief protection for bypass operation
• Chemical suction hose for detergent
• Mounting bolts and hardware
• Fittings and couplers
• Installation and operation manual

That matters more than it sounds. The usual way a pump swap turns into a weekend is discovering you need an unloader, then the right fittings for the unloader, then an adapter for the fitting. This package removes that chain.

RMW22G24-EZ-PKG specifications

• Flow: 2.2 GPM
• Pressure: 2,400 PSI
• Speed: 3,400 RPM
• Shaft: 7/8 in hollow
• Engine range: 4 to 7 HP
• Weight: 8 lbs
• Dimensions: 7 x 6 x 10.5 in
• Origin: Manufactured in Italy by Annovi Reverberi

Does it fit your engine?

Two things have to be true, and only two. The engine shaft has to be 7/8 in, and the engine has to be in the 4 to 7 HP range. Brand does not matter; shaft diameter and orientation do.

Measure the shaft before ordering rather than going by the engine’s name. Shaft sizes vary across a single manufacturer’s lineup, and an engine badged with the same displacement can carry a different shaft depending on the year and the market it was built for. If the shaft is 3/4 in, you want a different pump in the same family.

Where 2,400 PSI lands

2.2 GPM at 2,400 PSI is about 3.6 EBHP, which is why a 4 to 7 HP engine covers it comfortably. In practical terms:

• Good for: driveways, sidewalks, patios, decks, fences, siding, brick, vehicles, boats, RVs, farm equipment, job site cleanup, small fleet washing
• Not enough for: heavy grease removal, paint or coating prep, anything a surface cleaner larger than about 15 in will ask for

If you want to run a surface cleaner regularly, buy flow rather than pressure. 2.2 GPM will drive a small one slowly. A 4 GPM package will drive a proper one at working speed.

Building a machine around the RMW22G24-EZ-PKG

1. Fit the pump. Slide the 7/8 in hollow shaft onto the engine output shaft. It should go on without forcing.
2. Bolt it down with the supplied hardware and check that the pump sits square. A pump mounted under strain will leak at the head long before it wears out.
3. Plumb it. Garden hose to the inlet, high pressure hose to the outlet, detergent line to the chemical port. Fit an inlet filter if the package does not include one; this is the cheapest part on the machine and it protects everything downstream.
4. Fill with oil before the first start. Running a dry pump for even a few seconds damages seals.
5. Start and check at low pressure first, then set the unloader with the trigger open and confirm bypass behavior with it closed.

Budget an afternoon, not a weekend.

Making the RMW22G24-EZ-PKG last

• Check the oil level before each use
• Rinse the detergent filter and flush the system with clean water after chemical use
• Never run the pump dry, and never leave the trigger closed for long stretches
• Replace O-rings and seals at the first sign of weeping rather than waiting for a failure
• Run pump saver before any storage where it could freeze

Do those five things and this pump outlives two or three consumer machines. Skip the last one and it cracks the first cold night it spends in an unheated garage.

Not sure your engine shaft matches? Send the shaft diameter and engine HP and you will get a yes or a better-fitting part number.