Universal M4-30 Marine Diesel Engine

The Universal M4-30 is a powerful, durable, and fuel-efficient inboard marine diesel engine delivering 30 HP, designed to provide dependable auxiliary propulsion for sailboats and small cruising yachts. Known for its robust construction and straightforward mechanical design, the M4-30 is well-suited for boat owners seeking reliability and long-term serviceability.

Engine Design & Construction

The M4-30 features a 4-cylinder, 4-stroke diesel configuration with mechanical fuel injection, ensuring smooth power delivery and consistent torque across the operating range. Built on a proven industrial diesel platform adapted for marine use, the engine offers excellent durability and resistance to harsh marine environments.

A freshwater cooling system with heat exchanger maintains optimal operating temperatures while protecting internal components from corrosion. Its compact yet solid design allows flexible installation, while accessible service points simplify routine maintenance.

Performance & Efficiency

Producing 30 HP, the Universal M4-30 delivers reliable thrust for cruising, maneuvering, and docking. The 4-cylinder layout provides smoother operation and reduced vibration compared to smaller engines, enhancing onboard comfort during long passages.

The efficient mechanical injection system ensures economical fuel consumption, making the M4-30 a cost-effective choice for extended cruising and regular sailing use.

Marine Integration

The Universal M4-30 is compatible with marine gearboxes and conventional shaft-drive systems, making it suitable for both new installations and repower projects. Its balanced engine design contributes to quiet operation and improved handling in tight marina conditions.

Ease of Maintenance & Reliability

Designed for simplicity and ease of service, the M4-30 offers convenient access to filters, belts, and routine service components. Its mechanical layout reduces maintenance complexity and supports long-term reliability. Supported by the Universal marine engine legacy, it benefits from good parts availability and service knowledge.

Ideal Applications

The Universal M4-30 Marine Diesel Engine is ideal for:

• Sailboats and auxiliary propulsion systems

• Small to medium cruising yachts

• Coastal and inland waterways

• Owners seeking a reliable, smooth-running 4-cylinder marine diesel engine

Key Advantages

• Proven Universal marine diesel reliability

• Smooth 4-cylinder engine operation

• Fuel-efficient mechanical injection system

• Freshwater cooling with heat exchanger

• Reduced vibration and noise

• Easy maintenance and long service life

Technical Specifications

General

• Model: Universal M4-30

• Engine Type: 4-stroke, vertical, water-cooled marine diesel

• Fuel System: Mechanical fuel injection

• Aspiration: Naturally aspirated

• Number of Cylinders: 4 inline

Displacement & Combustion

• Displacement: Approx. 1.5 liters

• Bore × Stroke: Approx. 76 mm × 73 mm

• Combustion Chamber: Indirect injection diesel

Performance

• Rated Power: 30 HP @ approx. 3,000 RPM

• Rated Speed: Approx. 3,000 RPM

• Torque Characteristics: Smooth, strong low- and mid-range torque

• Fuel Consumption: Economical, dependent on load and propeller selection

Cooling & Lubrication

• Cooling System: Freshwater cooling with heat exchanger

• Lubrication System: Forced lubrication with gear-type oil pump

• Engine Oil Capacity: Approx. 4.5 liters

• Recommended Oil Type: Marine-grade diesel engine oil

Electrical System

• Starting System: 12 V electric start

• Alternator: 12 V marine alternator

Dimensions & Weight

• Overall Dimensions (L × W × H): Approx. 900 × 520 × 620 mm

• Dry Weight: Approx. 210–225 kg (engine only, excluding gearbox)

Drive & Installation

• Rotation (Crankshaft): Counter-clockwise (viewed from flywheel end)

• Drive Type: Inboard shaft drive

• Compatible Gearbox: Universal marine transmission

• Mounting: Flexible marine engine mounts

Service & Adjustment

• Valve Clearance (Cold): Intake: 0.20 mm / Exhaust: 0.25 mm

• Firing Order: 1 – 3 – 4 – 2

• Maintenance Access: Easy access to filters, belts, and routine service points