Keeping your yacht’s generator in top shape is essential for reliable power onboard and avoiding costly failures during critical times. This generator maintenance checklist offers a systematic approach to preventive care, aligned with typical inspection frequencies: daily, weekly, monthly, seasonal, and based on running hours. Whether you’re a seasoned skipper or new to yacht ownership, this guide helps you perform routine checks confidently and understand when to call a professional.
Table of Contents
Why a Generator Maintenance Checklist Matters
Yacht generators run intermittently, often sitting idle for long spells. That means problems like stale fuel, battery discharge, corrosion, and cooling flow issues can develop unnoticed. This checklist helps protect your investment, reduce emergency repairs, and keep power steady whether dockside or offshore.
Daily and Pre-Use Inspections
Before you start the generator each day or trip, perform these fast but crucial checks:
- Verify oil and coolant levels visually; look for drips or leaks beneath the unit
- Confirm belt condition and tension; replace or adjust if cracked or loose
- Check the general area for debris that might block air intakes or cooling vents
- Confirm the battery charge level and terminals are clean and tight
- Start the generator unloaded, listen for unusual noises, then gradually apply load and check for steady voltage and frequency
These simple routines can reveal leaks, loose connections, or early signs of overheating before they escalate.
Weekly Exercise Run
Run your generator at least 15-30 minutes weekly under a moderate load. This circulation lubricates the engine, prevents fuel degradation, charges the battery, and evaporates moisture buildup. Regular exercise keeps internal parts clean and operational, avoiding the “wet stacking” problem common in diesel gensets running too lightly wet stacking.
Monthly Checks
Once a month, perform a more thorough inspection:
- Clean and examine battery terminals and cables for corrosion
- Inspect air, fuel, and oil filters; replace clogged filters to maintain optimal airflow and fuel flow
- Check fuel lines and water separators for contamination or water accumulation
- Verify all electrical connections for tightness and signs of corrosion
- Confirm coolant concentration and fluid condition; top off or replace if discolored
Monthly attention prevents small issues from becoming costly repairs.
Seasonal and Yearly Maintenance
Perform these checks before the cruising season and at lay-up:
- Replace primary and secondary fuel filters to avoid clogs and injector damage
- Service or replace the raw water pump impeller to maintain cooling flow and prevent overheating
- Inspect the wet exhaust elbow and exhaust system for leaks, rust, or corrosion
- Flush and replace cooling system fluids per manufacturer specifications
- Perform a load bank test to assure the generator can sustain rated power under real load conditions
- Check the automatic transfer switch and control panel integrity
Regular seasonal service ensures your generator meets peak conditions during long passages or storms.
When to Call a Professional
Some tasks require specialized tools and experience:
- Valve lash adjustments
- Electrical regulation or alternator repairs
- Comprehensive fuel system cleaning
- Diagnosing persistent voltage or frequency instability
If your generator shows warning signs like exhaust steam, loud or irregular noises, frequent breaker trips, or unstable voltage, schedule professional service before operation.
Summary Table: Maintenance Tasks, Frequency, and Responsibility
| Task | Frequency | DIY or Professional | Notes |
|---|---|---|---|
| Oil and oil filter change | Every 100–150 hours | DIY or pro | Follow manual; log hours |
| Fuel filter replacement | Annual or 200–250 hrs | DIY or pro | Drain water separators regularly |
| Air filter inspection/replacement | Monthly or as needed | DIY | Keep intake clean |
| Raw water pump impeller | Yearly or 250–300 hrs | DIY or pro | Carry a spare on board |
| Battery inspection and cleaning | Monthly | DIY | Prevent corrosion |
| Cooling system flush and refill | Every 1–2 years | Professional | Critical for overheating prevention |
| Load bank testing | Annual | Professional | Checks full generator performance |
Frequently Asked Questions (FAQ)
How often should I run my generator if not in regular use?
At least 15 to 30 minutes weekly under load to keep fluids circulating and the battery charged.
What are early signs my generator needs service?
Look for leaks, unusual noises, exhaust steam, unstable voltage, or frequent breaker trips.
Can I perform filter replacements myself?
Yes, with proper guidance, but always use OEM parts and take care avoiding fuel spills.
When should I schedule professional service?
Annually or if you notice electrical irregularities, overheating, or persistent performance issues.
Are load bank tests necessary?
Yes, especially for diesel generators used intermittently, to avoid wet stacking and verify capacity.
Following this generator maintenance checklist regularly helps prevent breakdowns, extending your generator’s lifespan, and avoids unexpected failures at sea. It’s designed so even beginners can safely inspect and maintain their genset while clearly knowing when to seek professional help.