The boat mechanic's systems and tools: engine, drivetrain and electricity

To service a boat you must understand its systems and be able to work with them. A boat is a collection of systems that work together: the engine that provides power the driveline that directs power to the propeller the fuel and cooling system that keeps the engine running and the electrical system that powers instruments lights and start.

§Motor: inboard and outboard

Boat motors exist as inboard motors fixed inside the boat and outboard motors (outboards) that hang on the stern and can be tilted out of the water. They run on either petrol or diesel and each type has its own characteristics: petrol motors are often lighter and cheaper while diesel motors are reliable and widely used in larger boats and commercial work. You should know both.

§Fuel and cooling

The fuel system conducts fuel from the tank through filters and pumps to the engine — and clean filters and a water-free tank are essential because water and dirt in the fuel are a classic cause of engine stoppage. The cooling system often conducts seawater through the engine to remove heat and a faulty impeller or a clogged intake can quickly overheat the engine. Both systems are fixed check points during service.

§Driveline and propeller

The driveline transfers the engine's power to the propeller, which pushes the boat forward. It comprises gearbox, shaft and propeller, and must be properly adjusted and maintained, because fouling, wear or a damaged propeller costs both power and fuel. The propeller is checked for damage and fouling, and the shaft system's seals are checked for tightness.

§Electrical systems and electronics.

The electrical system powers start, lights, instruments, navigation, and pumps. Batteries, charging system, fuses, and wiring must be in order — and in a humid and salty environment, corrosion on electrical connections is a common source of faults. Modern boats also have electronics and engine control that require diagnostic equipment to troubleshoot.

• 01Standard mechanic's hand tools and torque wrench
• 02Multimeter for measuring voltage, current and resistance
• 03Diagnostic equipment for electronically controlled engines
• 04Compression gauge and special tools for the engine
• 05Equipment for preservation and frost protection.

§Safety equipment and environment

Work involves fuel, batteries, chemicals and work near water. Therefore, eye and respiratory protection, gloves and good ventilation are included, especially when working with fuel and solvents. Spills of oil and fuel must be prevented and collected — the marine environment is vulnerable and spills are both illegal and harmful. Working cleanly and collecting spills is part of the craft.