Comet Pressure Washer Pump Breakdown: Specs, GPM & Shaft Compatibility

Best for: Commercial cleaners with 1-inch shaft engines

Pros

• 4000 PSI high pressure
• 0 GPM flow rate
• Fully plumbed assembly

Cons

• Requires 11-13 HP engine
• Heavy 22.5-pound weight

The Comet ZWD4040G Fully Plumbed Pressure Washer is built for high-output commercial pressure washers. Delivering 4000 PSI at a flow rate of 4.0 GPM, this pump produces the volume needed to operate large rotary surface cleaners without loss of impact force. It features a 1-inch hollow shaft engineered for direct coupling to 3400 RPM commercial gas engines. Because the pump arrives fully plumbed, technicians can complete installation without sourcing separate unloader valves or inlet fittings.

This comet 1 inch shaft pressure washer pump suits commercial washing professionals and facility operators running 11 HP to 13 HP engines. Built with heavy metal construction, a brass manifold, and weighing 22.5 pounds, it provides solid durability under rigorous use. If you are upgrading equipment or replacing a unit on a commercial chassis such as a dewalt 3600 psi pump frame, verify shaft clearances before installation. Where smaller utility engines are installed, this pump yields to lighter 3/4-inch alternatives.

• Produces 4000 PSI at 4.0 GPM water volume
• Direct-drive 1-inch hollow shaft rated for 3400 RPM
• Durable metal and brass manifold construction weighing 22.5 pounds
• Fully plumbed triplex assembly ready for bolt-on installation

Best for: Mid-duty washing needing 2.5 GPM flow

Pros

• 2700 PSI working pressure
• 5 GPM water flow

Cons

• Shaft size not specified
• Unloader details omitted

The Comet Pumps Pressure Washer Pump provides an operational rating of 2700 PSI and a flow rate of 2.5 GPM. This balanced hydraulic output delivers sufficient pressure and rinse volume for driveway restoration, siding cleaning, and deck maintenance without overtaxing mid-range gas engines.

This model suits property owners and maintenance workers who need a direct 2.5 GPM replacement. However, the listing does not specify essential fitment details, such as engine shaft diameter, pump design type, construction materials, unloader configuration, or bolt pattern. Buyers should confirm their engine shaft size and plumbing connections against their existing unit, or select a fully documented Comet pump if exact mechanical dimensions are required.

• Delivers 2700 PSI maximum pressure
• Rated for 2.5 GPM water flow rate
• Built for intermediate pressure washing tasks
• Listing does not specify shaft size or unloader details

Best for: Residential washers with 3/4-inch shaft engines

Pros

• Built-in easy start
• Forged brass manifold
• Stainless steel plungers

Cons

• Capped at 2.4 GPM
• Not for 1-inch shafts

The BXD2527G Pressure Washer Pump 2700PSI is an axial plunger pump engineered for horizontal gas engines. Generating 2700 PSI at 2.4 GPM, this pump matches engines requiring up to 5.9 gross horsepower at 3400 RPM. Its 3/4-inch hollow steel shaft features an integrated key, allowing it to slide directly over the engine shaft. It also features a built-in easy-start mechanism that vents internal head pressure, preventing difficult pull starts and cord kickback.

This comet 3/4 shaft pressure washer pump suits homeowners and landscape crews operating 5 HP to 6.5 HP utility engines. If you run a standard residential power washer honda engine with a 3/4-inch horizontal shaft, this 11-pound pump mounts directly via standard gas engine flange patterns. The pump includes stainless steel plungers, stainless steel check valves, a forged brass manifold, an oil sight glass, a 1/2-inch FPT inlet, and a 3/8-inch male NPT outlet. Users needing higher flow for large surface cleaners should consider Comet triplex options instead.

• Outputs 2700 PSI at 2.4 GPM for engines up to 5.9 HP
• Engineered with a 3/4-inch hollow steel shaft and built-in key
• Forged brass manifold with stainless steel plungers and valves
• Equipped with double-sealing packings and built-in easy start

Best for: Industrial contractors running large 1-inch shaft rigs

Pros

• 4200 PSI industrial rating
• Plumbed VRT-3 unloader
• Abrasion-proof ceramic plungers

Cons

• Demands 1-inch engine shaft
• Requires high engine displacement

The Comet High Pressure Pumps direct-drive assembly (model 6305.0914.00) delivers top-tier performance in this lineup. This industrial comet triplex plunger pump generates 4200 PSI at 4.0 GPM at 3400 RPM. Arriving fully plumbed, it features the commercial VRT-3 unloader valve with easy-start functionality, an integrated thermal relief valve, and an inline fuel filter for comprehensive equipment protection.

Designed for commercial pressure washing contractors and heavy equipment operators, this 14.5-pound pump requires a 1-inch engine shaft and an engine producing at least 13 gross horsepower. Internal components feature forged bronze connecting rods with a lifetime warranty, hardened stainless steel piston guides, industrial ceramic plungers, and Buna-textile double-sealing V-packings. Its anodized aluminum finned crankcase maintains low operating temperatures during prolonged shifts. For operators with smaller utility engines, this model gives way to Comet 3/4-inch pumps.

• Rated for 4200 PSI working pressure at 4.0 GPM
• Direct-drive 1-inch shaft design for 3400 RPM engines
• Equipped with ceramic plungers and bronze connecting rods
• Arrives fully plumbed with VRT-3 unloader and thermal relief valve

Best for: Detailers needing chemical injection and unloader control

Pros

• Built-in chemical injector
• Adjustable unloader valve
• Elevated 2.8 GPM output

Cons

• Limited to 2500 PSI

The BXD3025G Pressure Washer Pump 2500PSI is an axial plunger pump engineered to provide elevated flow on medium-duty horizontal gas engines. Operating at 2500 PSI with 2.8 GPM, it delivers increased rinse capacity while demanding no more than 6.5 gross horsepower at 3400 RPM. It features an integrated adjustable unloader valve and a chemical injector, enabling users to regulate output pressure and apply cleaning detergents without extra accessories.

This comet bxd3025g unit suits mobile auto detailers, estate caretakers, and property managers operating 3 HP to 6.5 HP horizontal engines. If you are replacing a worn pump on a residential chassis such as a troy bilt pressure washer with a 3/4-inch solid shaft, this unit bolts directly in place using its 4-bolt gas flange. Built with a forged brass manifold, stainless steel check valves, and an oil sight glass, it provides reliable service. Those running full-time commercial wash operations should step up to a ceramic plunger triplex unit.

• Delivers 2500 PSI at an increased 2.8 GPM flow rate
• Configured with a 4-bolt flange for 3/4-inch horizontal shafts
• Includes adjustable unloader valve and built-in chemical injector
• Constructed with forged brass manifold and steel drive shaft

Best for: Equipment builders wanting a commercial bare pump

Pros

• Industrial ceramic plungers
• Bronze connecting rods
• 5-year limited warranty

Cons

• Sold as bare pump
• Requires separate unloader hardware

The Comet LWD3027 2700 PSI Pressure Washer is a commercial-grade bare pump engineered for long operating cycles. Delivering up to 2700 PSI and up to 3.0 GPM, it is built to pair with 3/4-inch shaft commercial and consumer gas engines displacement-rated at 200cc and above. Unlike entry-level axial pumps, this comet lwd3027 triplex pump utilizes forged bronze connecting rods with a lifetime warranty and abrasion-proof ceramic plungers for superior heat resistance.

This bare pump suits professional equipment builders and repair shops looking to retain their existing unloader hardware. Weighing 13 pounds and measuring 8 by 8 by 4 inches, it includes a 5-year limited warranty, high-efficiency stainless steel check valves, Buna-textile V-packings, and a finned anodized aluminum crankcase. Because it is sold strictly as a bare pump, users must supply an external unloader, thermal relief valve, and plumbing fittings prior to operation.

• Commercial triplex pump rated up to 2700 PSI and 3.0 GPM
• Fits 3/4-inch gas engine shafts on 200cc and larger engines
• Features heat-resistant ceramic plungers and bronze connecting rods
• Sold as a bare pump backed by a 5-year limited warranty