WP-4200-0MKB Gas Pressure Washer — Work Pro 4200 PSI with Kohler CH440
The Mi-T-M Work Pro WP-4200-0MKB pairs the Work Pro 4,200 PSI output with a 429cc Kohler CH440 OHV engine instead of the Honda GX390. Output is identical to the 0MHB variant: 4,200 PSI at 3.4 GPM, 14,280 cleaning units, through the same Mi-T-M crankshaft pump. The Kohler CH440 is a commercial-grade heavy-duty OHV with cast-iron cylinder sleeve, specified by buyers who run Kohler-powered fleets or prefer Kohler's commercial warranty structure.
WP-4200-0MKB Kohler CH440 Engine and Pump System
The CH440 at 429cc is the largest Kohler CH-series single-cylinder, used in heavy-load applications including commercial mowers, generators, and high-output pumps — the torque headroom ensures the pump stays at 4,200 PSI under continuous load.
4,200 PSI at 3.4 GPM (14,280 CU) — same output as the Honda variant; choose engine on service preference, not output difference
Mi-T-M crankshaft pump — brass manifold, thermal relief valve, Pressure Relief Start, in-line water strainer; rated for sustained heavy commercial use
Adjustable pressure unloader — variable pressure for different surfaces and applications without a nozzle change
50-foot × 3/8-inch wire-braided hose — adequate for fleet wash bays, building exteriors, and structural steel cleaning from a single position
10-inch flat-free tires, powder-coated steel frame — outdoor-rated construction for job site exposure
WP-4200-0MKB Applications and Environments
Municipal equipment yards, county road departments, and agricultural cooperatives that standardize on Kohler-powered equipment find the WP-4200-0MKB integrates cleanly into their existing service and parts program. The CH440's full-pressure lubrication system is better suited for sustained high-load operation than splash-lube designs — important when the machine runs 4–6 hours per day on fleet washing routes. Construction and demolition cleanup contractors use the 14,280 CU output for post-demo concrete and masonry cleanup. At 142 lbs, two-person handling is required for trailer loading; the machine is otherwise maneuverable on flat surfaces via the 10-inch tires.
WP-4200-0MKB 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 Kohler CH440 — 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 is the difference between the WP-4200-0MKB and WP-4200-0MHB?
Engine only: the 0MKB uses a 429cc Kohler CH440 OHV; the 0MHB uses a 389cc Honda GX390 OHV. Both produce 4,200 PSI at 3.4 GPM (14,280 CU) through the same Mi-T-M crankshaft pump. Choose based on your preferred engine service network.
What oil does the Kohler CH440 require?
Kohler specifies SAE 10W-30 for the CH440 in most operating temperatures. The CH440 uses full-pressure lubrication (not splash), which allows longer drain intervals — Kohler recommends every 100 hours or annually. Oil capacity is approximately 1.5 quarts.
Why does the CH440 use full-pressure lubrication and why does that matter?
Full-pressure lubrication pumps oil under pressure to bearing surfaces — it provides more consistent lubrication under high-load conditions and is less susceptible to oil starvation on slopes compared to splash-lube designs. For machines that operate at sustained high load (fleet washing, 4+ hour daily runs), full-pressure lube extends bearing and crankshaft service life.
Can the WP-4200-0MKB be ordered with a CARB-compliant engine for California?
The standard unit is a 49-state configuration not approved for California sale. Contact Mi-T-M directly for CARB-compliant engine availability on the 4,200 PSI platform before ordering for California delivery.
What is the Pressure Relief Start system and how does it work?
Mi-T-M's Pressure Relief Start vents the high-pressure side of the pump circuit during engine start, eliminating pump load on the crankshaft during pull-starting. This is particularly useful on heavy-displacement engines like the 429cc CH440 where compression resistance during starting increases physical effort.
What is the maximum input water temperature for the WP-4200-0MKB?
Mi-T-M Work Pro pumps are rated for cold water input (maximum approximately 140°F inlet temperature). This is not a hot water pressure washer — do not connect to a hot water supply or add inline heaters. For hot water operation, Mi-T-M's HSP series is the appropriate choice.
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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