Yanmar 4JH45E 53.8HP

The Yanmar 4JH45E is a 4-cylinder, vertical, water-cooled diesel marine engine producing approximately 53.8 mhp (metric horsepower) at 3000 rpm with natural aspiration and direct injection.

Power Output: 39.6 kW / 53.8 mhp at 3000 rpm Displacement: 2.19 L (134 cu in) Cylinders: 4 Combustion: Direct injection (mono plunger pump) Aspiration: Natural Alternator: 12 V, 125 A Dry Weight (no gear): ~201 kg (443 lbs) Control: Mechanical

It uses direct fuel injection with a mono plunger pump, which provides efficient combustion and reliability typical of Yanmar inboard diesels.

Check engine oil level: daily or before each outing. Change engine oil & filter: around every 50–100 hours or as specified in the manual. Fuel filter servicing: every 250 hours or yearly. Cooling system, belts, hoses and seawater impeller: periodic checks recommended. Always follow the exact schedule in the official operation manual for your model.

Basic checks (oil level, coolant, belts) can be done by owners with mechanical skills. However, major maintenance and diagnostic work (especially on electronically controlled systems) is best done by an authorized Yanmar dealer or technician to protect performance and warranty.

Yanmar recommends using engine oils and coolants that meet the specifications in the owner’s manual for your specific engine and operating conditions. Yanmar branded fluids are available and formulated for their diesel engines.

Common issues include low battery charge, air in the fuel system, water in the fuel, or starter motor problems. Begin troubleshooting with basic checks, but for complex issues, contact a certified marine technician.

Warranty length and coverage vary by region. Always check your warranty handbook for specific details.