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