CM-4200-0MMB Gas Pressure Washer — 4200 PSI ChoreMaster for Heavy Equipment Washing
The Mi-T-M ChoreMaster CM-4200-0MMB is the highest-output model in the ChoreMaster line, producing 4,200 PSI at 3.4 GPM — 14,280 cleaning units. Powered by a 420cc Mi-T-M OHV engine and a crankshaft pump built for sustained commercial duty, it handles fleet washing, heavy construction equipment, and concrete surface stripping where the 3,600 PSI model works too slowly. Cold water only; for grease and petrochemical removal, pair it with a chemical injector and appropriate detergent.
CM-4200-0MMB Cleaning Power and Engine Comparison
The 420cc displacement is nearly double the CM-3000's 212cc engine — the added torque reserves allow the pump to maintain rated pressure through surface cleaners and turbo nozzle attachments without the engine laboring.
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4,200 PSI at 3.4 GPM (14,280 CU) — handles concrete stripping, fleet washing, and rust removal tasks that require sustained high pressure over large surface areas
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420cc Mi-T-M OHV engine — Mi-T-M's largest single-cylinder OHV; more torque reserve than the 300cc CM-3600 engine, critical when running surface cleaner attachments that add load
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Mi-T-M crankshaft pump — commercial-duty triplex design; brass manifold, thermal relief valve, in-line water strainer standard
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Adjustable pressure unloader — allows pressure reduction for vehicle washing and painted surfaces without nozzle changes
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10-inch flat-free tires — stable on gravel lots, construction debris, and loading dock surfaces
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Mi-T-M Pressure Relief Start — reduces compression during pull-starting; easier cold starts on heavy-displacement engines
CM-4200-0MMB Applications and Environments
Fleet maintenance operations washing semi-trucks, trailers, and heavy equipment will find the CM-4200-0MMB sustains the output needed for full-vehicle washing without the duty-cycle limitations of a smaller engine. Construction contractors use it for post-pour concrete form cleaning and foundation prep where cured concrete residue requires maximum PSI. Municipalities and county road departments running equipment wash stations keep these units for seasonal cleaning of plow trucks, road graders, and utility vehicles. The 142 lb unit fits a standard job trailer but requires a minimum two-person loading.
CM-4200-0MMB 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. Not for sale in California without CARB-compliant engine — consult factory.
Specifications
| PSI |
4,200 PSI at rated flow |
| GPM |
3.4 GPM |
| Cleaning Units |
14,280 CU (PSI × GPM) |
| Engine |
420cc Mi-T-M OHV |
| Pump Type |
Mi-T-M Crankshaft |
| Unloader |
Adjustable Pressure |
| Hose |
50 ft × 3/8 in wire-braided |
| Nozzles Included |
15°, 25°, detergent |
| Net Weight |
142 lbs |
| Dimensions (L × W × H) |
40 × 22.5 × 24.5 in |
| Hot/Cold |
Cold water only |
| California Sale |
Not for sale in CA (non-CARB); consult factory |
Documents
Spec Sheet
Manual
