WP-4200-0MHB Gas Pressure Washer — Work Pro 4200 PSI with Honda GX390
The Mi-T-M Work Pro WP-4200-0MHB is the highest-output model in the Work Pro direct-drive line, producing 4,200 PSI at 3.4 GPM — 14,280 cleaning units — driven by a 389cc Honda GX390 OHV engine and a Mi-T-M crankshaft pump. The GX390 is Honda's heavy-duty commercial single-cylinder, common in concrete saws, construction compactors, and high-flow pumps — it carries the output headroom needed to sustain 14,000+ CU output through surface cleaners and extended cleaning runs. Cold water only.
WP-4200-0MHB High-Output Cleaning Configuration
At 14,280 cleaning units, this unit is 87% more productive than the 7,680 CU WP-3200 — the difference registers immediately on large concrete areas, fleet vehicles, and heavy equipment where throughput is the productivity constraint.
4,200 PSI at 3.4 GPM (14,280 CU) — sufficient for concrete stripping, rust removal, fleet washing, and structural steel cleaning at commercial throughput rates
389cc Honda GX390 OHV engine — Honda's commercial heavy-duty single-cylinder with 11.7 ft-lbs torque; wide service network and GX-series parts availability
Mi-T-M crankshaft pump with brass manifold — commercial-duty triplex design; thermal relief valve, in-line water strainer, and Pressure Relief Start standard
Adjustable pressure unloader — scale pressure down for vehicle washing without nozzle changes
50-foot × 3/8-inch wire-braided hose — reaches across standard truck wash bays and equipment storage areas without repositioning
10-inch flat-free tires, 40-inch powder-coated steel frame — stable on job site surfaces; resists corrosion for outdoor storage
WP-4200-0MHB Applications and Environments
Fleet maintenance shops washing Class 8 semi-trucks and tanker trailers find the 14,280 CU output reduces wash time versus lower-output machines. Concrete contractors use it for cured form release removal and slab preparation where 3,600 PSI works too slowly on mineral-bond residue. Agricultural operations cleaning grain combines, planters, and applicator booms need the GPM to move heavy soil load. Property restoration contractors running post-storm mud and debris removal from parking structures and building exteriors get meaningful coverage at 3.4 GPM. The 142 lb weight requires two-person handling for trailer loading.
WP-4200-0MHB GPM, PSI, and Nozzle Configuration
Rated at 3.4 GPM at 4,200 PSI (14,280 cleaning units) at rated flow. Includes 15°, 25°, and detergent quick-connect nozzles; 50-foot × 3/8-inch wire-braided hose; 36-inch two-piece lance with trigger gun. Cold water only. 49-state Honda GX390 — not for sale in California.
We supply contractors, restoration companies, property managers, schools, government agencies, and other tax-exempt organizations.
How to place a tax-exempt order:
Write to us through our Contact Us page or email info@uscleaningtools.com and attach your valid tax exemption certificate (state resale or exemption certificate).
We verify your certificate and mark your account tax-exempt — usually within one business day.
Place your order and sales tax will not be charged.
For volume pricing or purchase orders, call +1 (978) 295-7538.
Shipping & Returns
Free shipping on most brands for orders over $300, delivered to the lower 48 states. Any brand-specific freight rate is shown at checkout before you pay.
Processing & delivery: in-stock orders are processed within 1–2 business days and typically deliver in 5–7 business days. Tracking is emailed within 24 hours of shipment. Built-to-order and backordered equipment shows its lead time on this page.
Freight deliveries: inspect your equipment on arrival and note any damage on the delivery receipt. Items damaged in transit or defective on arrival are fully covered at no cost to you.
Cancellations: cancel any time before your order ships for a full 100% refund.
30-day returns: return unused equipment in its original packaging within 30 days of delivery. Change-of-mind returns are subject to a restocking fee. To start a return, email info@uscleaningtools.com or call +1 (978) 295-7538.
What makes the Honda GX390 appropriate for 4,200 PSI operation?
The GX390 produces 11.7 ft-lbs of torque at rated RPM — more than the GX270's output — providing headroom for the crankshaft pump to maintain 4,200 PSI under load without the engine bogging when working through surface cleaners or at maximum flow rate.
How does the WP-4200-0MHB compare to the WP-3600-0MHB?
The WP-4200 adds 600 PSI and 0.6 GPM more, uses a 389cc Honda GX390 vs 270cc GX270, and produces 14,280 vs 10,080 cleaning units — 42% more productivity. Step up to the WP-4200 when your jobs require concrete stripping or sustained heavy equipment washing where the 3,600 PSI output is too slow.
Is the WP-4200-0MHB available for California sale?
No — the Honda GX390 on this unit is a 49-state non-CARB engine. Contact Mi-T-M for CARB-compliant configurations. The WP-4200-0MKB (Kohler CH440) may be available in a CARB variant.
What surface cleaner size is compatible with the WP-4200-0MHB?
Surface cleaners rated for 4,000–5,000 PSI and up to 3.4 GPM flow are compatible. An 18–21 inch surface cleaner is the practical match for this flow rate — larger units may spin unevenly at 2.8 GPM or below, and smaller units waste the available GPM.
What nozzles are included and can I add a 0° tip?
Included: 15°, 25°, and detergent quick-connect nozzles. A 0° nozzle is not included. Mi-T-M sells compatible 0° quick-connect tips separately — use with caution; 4,200 PSI through a 0° tip can cut into softwood, etch concrete, and remove coatings.
What is the oil capacity and service interval for the Honda GX390?
The GX390 holds approximately 1.16 quarts of SAE 10W-30. Change at the 5-hour break-in interval, then every 100 hours or annually. Check oil level before every use — the GX390 does not have a low-oil shutoff in all configurations.
Frequently Asked Questions
1. What payment methods can I use?
We accept Visa, MasterCard, American Express, Diners Club, Discover, major debit cards, and digital wallets like PayPal, Google Pay, Meta Pay, and Apple Pay.
2. When will my payment be processed?
Your credit/debit card or PayPal account will be charged when you place your order. Secure payment processing protects your information.
3. Will I receive an order confirmation?
Yes, a confirmation email will be sent to the provided email address once the order is placed.
4. How long does it take to process an order?
Orders are processed within 1-2 business days and then prepared for shipment.
5. How long does it take for my order to arrive?
Estimated arrival time (ETA) is 5-7 business days for all orders.
6. Do you offer warranty?
All our products come with a manufacturer warranty of at least 1 year, depending on the brand.
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