Yanmar 4LV250 High-Output Inboard Diesel Engine

Description

Drive high-speed coastal interceptors and sport cruisers to top planing velocities with the Yanmar 4LV250 Inboard Diesel Engine. This 2.755L 4-Cylinder marine diesel generates 250 BHP at 3,800 RPM and 195 BHP continuous at 3,640 RPM. High-pressure 2,500 bar common-rail injection demands 2-micron fuel pre-filtration, and chain-driven camshafts require strict compliance with manufacturer engine oil specifications.

A parent bore high-grade cast iron block integrates stiffening ribs to handle intense internal combustion loads. The single-piece rigid cast iron cylinder head features dual overhead camshafts driven by a timing chain. Electrical systems run on an isolated 12V 2-pole earth circuit with NMEA 2000 output, a 2.5 kW starter, and a 12V 130A alternator. Dimensions span 39.4in long, 29.7in wide, and 30.4in high, weighing 785 lbs. Oil pan capacity holds 2.11 US gal.

Key Features of Yanmar 4LV250

Performance boaters buy Yanmar 4LV250 high-output inboard diesel engines to repower 26ft to 38ft sport tenders and center consoles. Marine architects select this package for commercial workboat diesel engine repower installations in coastal interceptors.

• Denso common-rail fuel injection operates at 2,500 bar pressure to optimize fuel burn
• Turbochargers with seawater-cooled charge air intercoolers force dense air into cylinders for instant torque
• Tubular freshwater heat exchangers protect internal cast iron water jackets from raw seawater corrosion
• High-output 12V 130A alternators recharge large marine house battery banks during harbor transits
• NMEA 2000 CAN-bus data networks stream engine parameters straight to modern helm multifunction displays
• SAE 4 flywheel housings connect directly to Yanmar KM4A1, ZF 45A, ZF 63IV, or ZT370 sterndrives
• Rigid chain-driven overhead camshafts maintain exact valve timing across all operating RPM ranges

Bench Dynamometer Load Test Output

Dynamometer test records confirm 250 BHP peak output at 3,800 RPM and 195 BHP continuous output at 3,640 RPM under high-output ratings. Turbo boost pressure stabilizes at 1.95 bar during continuous full-power runs. Freshwater cooling circuits hold engine block temperature at 182°F under sustained maximum power dyno pulls. Engine oil pressure maintains 55 PSI across operational engine speeds. Shaftline installation permits up to 15° static inclination angles. Crankshaft journal runout remains below 0.0004in TIR to protect bearings against deflection fatigue. Exhaust temperatures stay below 1,220°F during full power runs.

Field Operation Maintenance Service Rules

Electronic throttle controls provide light lever action with under 2 lbs of hand resistance. Do not install this 3,800 RPM high-output engine in heavy slow-speed displacement push-boats or vessels operating in shallow mud shallows without raw-water strainers. Operators must supply clean ultra-low sulfur fuel and maintain 2-micron fuel water separator filtration to protect high-pressure fuel pumps.

• Drain engine oil and change spin-on oil filter cartridges every 250 operating hours
• Inspect raw water pump impellers and check heat exchanger zinc anodes every 250 hours
• Replace the primary 2-micron fuel water separator filter cartridge every 250 engine hours

Factory Warranty Shipment Parts Manifest

Yanmar Marine provides a 2-Year limited warranty backed by 3-Year major component structural coverage. The shipment crate contains the 4LV250 diesel engine core, KM4A1 marine gearbox, 12V 130A alternator, 2.5 kW starter motor, flexible vibration mounts, digital display panel, wiring harness, and factory technical manuals.