A Simple Guide for Administrative & Front Office Staff in Marinas
A main engine service (service κύριας μηχανής) is one of the most common maintenance jobs performed on yachts/catamarans every season. Understanding the steps helps administrative staff communicate better with technicians, explain costs to clients, and track work progress confidently.
In this post, we will explain a standard annual service for a yacht main engine such as Yanmar or engines commonly installed in catamarans (καταμαράν).
Step 1 — Engine Oil Change
Changing the Engine Oil (Αλλαγή λαδιών μηχανής)
What is Engine Oil (Λάδι μηχανής)?
Engine oil lubricates the internal moving parts of the main engine (κύρια μηχανή) and prevents overheating and wear.
Typical Tasks
Technician will:
Drain old oil (αφαίρεση παλιού λαδιού)
Replace oil filter (φίλτρο λαδιού)
Add new oil (νέο λάδι)
Check oil level (έλεγχος στάθμης λαδιού)
Why this matters for the office
You will often see in a quotation:
Engine oil
Oil filter
Labor for oil change
This is usually the first and most basic service task.
Step 2 — Fuel Filter Replacement
Changing the Fuel Filters (Αλλαγή φίλτρων καυσίμου)
What is a Fuel Filter (Φίλτρο καυσίμου)?
It removes dirt and water from the fuel before it reaches the engine.
There are usually:
Primary filter (πρωτεύον φίλτρο)
Secondary filter (δευτερεύον φίλτρο)
Typical Tasks
Technician will:
Remove old filters (αφαίρεση παλιών φίλτρων)
Install new filters (τοποθέτηση νέων φίλτρων)
Bleed fuel system (εξαέρωση συστήματος καυσίμου)
Common Symptoms of a Problem
Engine stops suddenly
Loss of power
Difficult starting
Step 3 — Impeller Replacement
Replacing the Water Pump Impeller (Αλλαγή ιμπέλερ)
What is an Impeller (Ιμπέλερ)?
A rubber component inside the sea water pump (αντλία θαλασσινού νερού) that pushes cooling water through the engine.
It is one of the most frequently replaced parts.
Typical Replacement Interval
Usually:
Every year
OREvery 200–300 engine hours (ώρες λειτουργίας)
Why it is critical
If the impeller fails:
The engine may overheat (υπερθέρμανση).
Step 4 — Checking the Cooling System
Inspecting the Cooling System (Έλεγχος συστήματος ψύξης)
What is the Cooling System (Σύστημα ψύξης)?
It controls the engine temperature using:
Seawater (θαλασσινό νερό)
Coolant (ψυκτικό υγρό)
Technician checks
Hoses (σωλήνες)
Heat exchanger (εναλλάκτης θερμότητας)
Coolant level (στάθμη ψυκτικού)
Step 5 — Belt Inspection
Checking Engine Belts (Έλεγχος ιμάντων)
What is a Belt (Ιμάντας)?
A belt connects the engine to components like:
Alternator (δυναμό)
Water pump (αντλία νερού)
Technician checks
Belt tension (τάση ιμάντα)
Cracks (ρωγμές)
Wear (φθορά)
Step 6 — Battery and Electrical Check
Checking the Electrical System (Έλεγχος ηλεκτρικού συστήματος)
What is the Battery System (Σύστημα μπαταριών)?
It provides power to start the engine and operate onboard systems.
Technician checks
Battery voltage (τάση μπαταρίας)
Connections (συνδέσεις)
Charging system (σύστημα φόρτισης)
Typical Duration of a Main Engine Service
Διάρκεια Service Κύριας Μηχανής
Usually:
2–4 hours per engine
(ανά μηχανή)
Example:
Catamaran (καταμαράν):
2 engines
Total service time:
4–8 hours
Typical Parts Used in a Standard Service
Συνήθη Ανταλλακτικά Service
Engine oil (λάδι μηχανής)
Oil filter (φίλτρο λαδιού)
Fuel filters (φίλτρα καυσίμου)
Impeller (ιμπέλερ)
Gaskets (τσιμούχες)
Coolant (ψυκτικό υγρό)
