Centurion P4+ Direct Drive Triplex 4400 PSI 4.2 GPM Pressure Washer Bare Pump – 85.120.142B

The professional’s powerhouse — compact, efficient, and built to perform under pressure.

Built for Maximum Cleaning Power

The Centurion P4+ Direct Drive Triplex Pressure Washer Pump (85.120.142B) is the ideal combination of high-pressure performance, reliability, and compact design. Manufactured by CP, a global leader in precision pump engineering, the P4+ delivers 4,400 PSI of cleaning force at 4.2 GPM — making it one of the most capable and dependable direct-drive pumps in its class.

Engineered for gas-powered systems, this triplex ceramic plunger pump is built for serious professionals who expect commercial-grade reliability and long-term durability from their equipment. Whether you’re restoring concrete, maintaining fleets, or managing industrial cleaning operations, the Centurion P4+ is designed to deliver relentless power and smooth, consistent performance with every use.

Technical Overview

• PMR PART #: 85.129.142B

• BARE PUMP PART #: 85.120.142B

• PUMP MANUFACTURER: CP

• PUMP MODEL: CTG2S

• DRIVE TYPE: Direct Drive (Gas)

• SHAFT SIZE: 1"

• PUMP STYLE: Triplex

• MAX PSI: 4,400

• MAX GPM: 4.2

• UNLOADER TYPE: External

• PLUNGER (PISTON): Ceramic

• INLET SIZE: 3/4" GHF

• DISCHARGE SIZE: 3/8" Brass QC

• SOAP INJECTOR: Fixed

• MANIFOLD TYPE: Brass

• RPM: 3,450

• MAX INLET TEMP: 60°C / 140°F

• THERMAL RELIEF VALVE: 85.300.022

• OIL CAPACITY: 13.5 fl oz

• OIL TYPE: 30W Non-Detergent

• WEIGHT: 18 lbs

• WARRANTY: 7 Years

Designed for Professional-Grade Cleaning

The Centurion P4+ was built to provide maximum pressure and reliability for demanding cleaning environments. With its triplex plunger design, it delivers powerful, steady water output that eliminates pulsation and vibration, ensuring a smooth and efficient flow ideal for consistent professional use.

Operating at 3,450 RPM, this pump is designed to mount directly to gas-powered engines with a 1-inch shaft, transferring power efficiently for minimal energy loss. The result is a compact, highly efficient pump capable of tackling the toughest cleaning jobs without sacrificing reliability or performance.

Whether you’re a professional contractor, fleet manager, or property maintenance technician, the P4+ offers the perfect balance of pressure, flow, and durability for daily operation in commercial and industrial settings.

Key Features

Triplex Ceramic Plunger Design

The triplex design — featuring three synchronized ceramic plungers — ensures balanced, pulse-free operation. Ceramic plungers are exceptionally durable and heat-resistant, significantly reducing wear on seals and extending pump life under continuous, high-pressure operation.

This setup guarantees long-lasting performance, smoother flow, and lower vibration — all critical advantages for professional cleaning systems running for hours at a time.

Brass Manifold Construction

The solid brass manifold provides superior corrosion resistance and structural integrity under high pressure. Unlike cast aluminum or zinc housings, brass maintains its strength over years of use, even in harsh water conditions or when exposed to cleaning chemicals. This ensures consistent sealing, precise tolerances, and dependable performance throughout the pump’s service life.

External Unloader System

The external unloader gives operators full control over system pressure while simplifying maintenance and serviceability. This design allows quick adjustments for different cleaning tasks and makes replacement easy without disassembling the pump body. It also enhances cooling during bypass, reducing thermal stress on internal seals.

Fixed Soap Injector

The built-in fixed soap injector enables consistent detergent application, allowing operators to switch between cleaning and rinsing seamlessly. Its simple, low-maintenance design makes it ideal for contractors who need dependable chemical injection without constant recalibration.

Thermal Relief Protection

To safeguard the pump during idle periods, the thermal relief valve (85.300.022) automatically releases overheated water, replacing it with cooler water from the supply line. This prevents excessive heat buildup that could damage seals, plungers, and valves — a vital feature for extending pump life during long workdays.

High-Efficiency Direct Drive System

The direct drive configuration connects the pump directly to the engine shaft, eliminating pulleys and belts for a compact and efficient design. This reduces vibration, simplifies installation, and ensures a clean transfer of power from the engine to the pump.

The result? A lightweight, space-saving setup with fewer moving parts and lower maintenance requirements — perfect for mobile pressure washer systems and compact builds.

Built for Heavy-Duty Applications

The Centurion P4+ is the ultimate solution for professional and industrial cleaning applications where power, performance, and reliability are critical. Its 4,400 PSI output and 4.2 GPM flow rate strike the perfect balance between pressure and volume, giving you the force to blast away grime while maintaining efficient coverage for large surfaces.

Common Applications Include:

• Fleet and Equipment Washing: Removes heavy grease, mud, and oil from trucks, trailers, and construction equipment.

• Concrete and Masonry Cleaning: Strips away dirt, paint, algae, and buildup from walkways, patios, and driveways.

• Industrial Maintenance: Ideal for factories, warehouses, and manufacturing facilities.

• Agricultural Equipment Cleaning: Keeps tractors, harvesters, and machinery operating cleanly and efficiently.

• Surface Preparation: Perfect for cleaning surfaces before painting, sealing, or coating.

The P4+ is versatile enough for both stationary and mobile configurations, making it a popular choice for pressure washer manufacturers, system builders, and end users alike.

Durable Construction and Long-Term Reliability

Every Centurion pump is built to meet the highest engineering standards — and the P4+ is no exception. From its hardened crankshaft and heavy-duty bearings to its precision-milled seals, every component is designed for performance under pressure.

Key Durability Features:

• Hardened crankshaft and connecting rods for balanced motion and minimal wear.

• Oversized bearings that distribute load evenly for smooth, quiet operation.

• Corrosion-resistant brass manifold for extended longevity in wet environments.

• Ceramic plungers that reduce friction and prevent scoring.

• Premium oil-lubricated crankcase for consistent lubrication and cooling.

This attention to material quality and engineering precision ensures the P4+ can withstand years of professional use with minimal maintenance.

Performance and Efficiency

Delivering up to 4,400 PSI of pressure and 4.2 GPM of flow, the Centurion P4+ produces the ideal combination of power and efficiency for professional cleaning. It easily removes grime, paint, oil, and debris from virtually any surface while maintaining consistent pressure across varied loads.

At 3,450 RPM, the P4+ runs smoothly and efficiently on standard 13–15 HP gas engines. Its direct drive configuration provides immediate responsiveness and minimal lag — allowing for faster start-up, improved efficiency, and reduced noise compared to traditional belt-drive systems.

Simplified Maintenance and Serviceability

The Centurion P4+ is designed for ease of maintenance, ensuring minimal downtime and maximum productivity for professionals in the field.

Maintenance Advantages:

• External unloader for easy pressure adjustment and quick replacement.

• Brass quick-connect fittings for fast hose attachment and removal.

• Fixed soap injector for maintenance-free chemical application.

• Thermal relief valve for automatic temperature regulation.

• Oil sight glass for easy monitoring of oil condition and level.

Regular maintenance is straightforward: check oil levels, inspect fittings, and replace seals as needed. With proper care, this pump will deliver years of reliable, consistent performance.

Installation and Compatibility

The Centurion P4+ is engineered for easy installation and direct compatibility with most 1-inch horizontal shaft gas engines, including popular models like Honda GX390, Kohler CH440, and Powerease R420.

Installation Steps:

1. Align the pump’s 1" hollow shaft with the engine shaft.

2. Secure the pump using standard mounting bolts.

3. Connect the 3/4" GHF inlet and 3/8" brass quick-connect discharge fittings.

4. Fill with 13.5 fl oz of 30W non-detergent oil before first use.

5. Adjust the external unloader for desired pressure output.

6. Verify operation and thermal relief valve functionality.

This direct-drive setup is lightweight, compact, and efficient — ideal for portable pressure washer builds or replacement applications.

Built to Run Cool and Clean

Heat is one of the biggest threats to pump longevity, and the Centurion P4+ is engineered to manage it efficiently. The ceramic plungers, brass manifold, and thermal relief valve work together to dissipate heat, while the oil-lubricated crankcase ensures smooth, friction-free operation.

With a maximum inlet temperature of 60°C (140°F), the P4+ can handle warm water input safely, making it versatile enough for a wide range of cleaning applications — from degreasing to industrial maintenance.

Applications

The P4+ shines in a broad range of professional and industrial environments, including:

• Fleet Maintenance – Keeps trucks, buses, and heavy machinery spotless.

• Construction Sites – Cleans concrete, brick, and building exteriors with ease.

• Property Maintenance – Restores siding, decks, and walkways.

• Manufacturing Facilities – Removes oil, grease, and contaminants.

• Agricultural Equipment – Keeps tractors and implements clean and corrosion-free.

Whether stationary or mobile, the P4+ provides unmatched power and reliability.

Backed by a 7-Year Warranty

The Centurion P4+ is backed by a 7-year manufacturer’s warranty, proving CP’s commitment to quality and long-term reliability. Each pump is precision-tested for pressure, flow, and leak integrity before leaving the factory, ensuring you receive a product that performs flawlessly from day one.

This warranty gives professionals the confidence to depend on their pump for years of continuous service — no compromises, no surprises.

Product Highlights

• Model: CTG2S (Centurion P4+)

• PMR Part #: 85.129.142B

• Bare Pump #: 85.120.142B

• Drive Type: Direct Drive (Gas)

• Pressure / Flow: 4,400 PSI @ 4.2 GPM

• RPM: 3,450

• Manifold: Brass

• Plungers: Ceramic

• Unloader: External Adjustable

• Soap Injector: Fixed

• Thermal Relief Valve: 85.300.022

• Oil Capacity: 13.5 fl oz (30W Non-Detergent)

• Weight: 18 lbs

• Warranty: 7 Years

The Centurion P4+ Direct Drive Triplex 4400 PSI 4.2 GPM Pressure Washer Bare Pump (85.120.142B) combines professional-grade performance with long-term reliability. With a brass manifold, ceramic plungers, external unloader, and fixed soap injector, it’s designed to handle the toughest cleaning tasks with precision and power.

Operating at 3,450 RPM and delivering 4,400 PSI, it’s the perfect upgrade or replacement for high-performance gas-powered pressure washers. Backed by a 7-year warranty, the P4+ represents the pinnacle of Centurion’s engineering — where quality, power, and endurance come together.

Centurion P4+ — Unmatched pressure. Unstoppable performance. Built for professionals who demand the best.