Start with how the generator is used
A marine generator is often treated as something that either starts or does not. In practice, the useful question is not whether it ran last weekend. It is whether the starting, charging, cooling, fuel and electrical systems around it are being checked in a way that matches how the vessel is used.
For a boat that sits on a marina berth most weeks, the generator may only run occasionally. For a vessel that spends time away from shore power, it may be part of the normal daily routine. Both patterns produce different servicing priorities.
Write down how often the generator runs, what it powers while it is running, and whether it is used for short top-ups or long periods under load. This gives a much better picture than an hours figure on its own.
Watch the signs between services
Some symptoms are easy to dismiss because the generator still starts. A slow start, a change in exhaust note, a new vibration, a fuel or oil weep, or a battery that needs more charging than before are all worth recording.
Electrical symptoms can be less obvious than mechanical ones. A generator may run but fail to deliver charge properly, produce unstable voltage, or trip a breaker when a particular load is applied. These are reasons to arrange a scheduled inspection rather than to keep running the set until it fails.
If the generator is used for charging batteries, note how quickly the batteries accept charge and whether that behaviour has changed. If it powers equipment directly, note anything that has become intermittent or noisy.
- How the generator starts compared with previous use.
- Any change in exhaust note, vibration or noise.
- Whether charging takes longer or stops earlier than before.
- Equipment that trips, resets or behaves differently under load.
Build servicing around real use
A service schedule should reflect the vessel, the equipment and the way it is operated. Calendar intervals, running hours, fuel condition and the load profile all matter. A generator that runs lightly and often is not used in the same way as one that runs heavily for shorter periods.
When the generator is part of a wider charging system, it is worth looking at the batteries, chargers and alternator at the same time. A generator problem can sometimes be a symptom of a charging problem elsewhere aboard.
If the vessel has recently changed ownership or the service history is unclear, begin with a baseline check. Record what is there, what condition it is in and what needs attention. That makes later servicing easier to plan.
What to include in an enquiry
For a generator service enquiry, include the vessel type, generator make and model if known, how often it runs, and anything that has changed. If the service history is known, include when it was last serviced.
Maritime Electrical does not list generator servicing among its services. For mechanical generator servicing, contact the manufacturer or an appropriate generator service provider. If the issue is a separate onboard electrical fault, describe that fault when contacting an electrician.
- Vessel type and approximate length.
- Marina or berth location.
- Generator make and model, if known.
- How often it runs and what it powers.
- Any change in starting, running or charging behaviour.
- When it was last serviced, if known.
Where this fits with maintenance
Generator servicing and onboard electrical maintenance are different jobs. A generator service provider can advise on the generator itself. Maritime Electrical offers electrical maintenance and fault-finding for onboard electrical systems, but does not claim to service generators.
If you are reporting a separate electrical fault aboard, describe the affected system and symptoms. Do not assume the generator itself is included in an electrical maintenance visit.
Build a useful service record
A short record is more useful than trying to remember the last time the generator was used. Note the date, the running hours if the display provides them, what the set was powering and anything unusual during the run. Keep the entry factual: “took longer to start than last time” is more useful than “probably the starter”.
Keep invoices, service notes and the generator manual together if possible. If the equipment has changed hands with the vessel, write down what information is missing rather than filling gaps with guesses. An incomplete history is still a useful starting point for a baseline check.
When a symptom repeats, record whether it happens on every start or only after the generator has been idle, warmed up or connected to a particular load. That pattern can help distinguish a one-off event from a change that deserves investigation.
- Date and running hours, if available.
- What the generator was powering.
- Starting, running or charging changes.
- Recent service or equipment changes.
Use the manufacturer guidance for intervals
There is no single service interval that suits every generator and every vessel. The maker’s manual is the starting point for the model-specific schedule. Running hours, periods of light use, the environment and the work the set performs can all affect what needs attention.
If the manual is missing, identify the make and model before choosing a schedule. A service provider can help establish what information is available and what should be checked first. Avoid relying on a generic interval copied from another generator; similar-looking sets can have different requirements.
A service plan should also distinguish routine maintenance from a response to a new symptom. A scheduled service does not explain away a warning, a leak or a sudden change in how the set runs.
When not to keep running the generator
Follow the generator maker’s instructions if a warning appears or the set behaves abnormally. Do not keep restarting it to see whether a fault clears, and do not remove guards or open electrical enclosures to investigate. A visible leak, smoke, unusual heat, repeated breaker trips or a new severe noise is a reason to stop and arrange an appropriate inspection.
If you are unsure whether a change is safe to operate with, record what you can from a safe position and ask for advice before relying on the generator. The goal is to provide useful information without turning an observation into a risky repair attempt.
A practical next step
If you are not sure when the generator was last checked, start with the manufacturer’s service guidance or contact a generator service provider. Record how it is used and what has changed.
For a separate onboard electrical issue, Maritime Electrical’s maintenance and fault-finding page explains the electrical work it offers.