Beta Marine Beta 20 maintenance schedule
The Beta Marine Beta 20 service schedule as Beta Marine publishes it, set out as a checklist for the crew: the work due at 150, 250, 500, and 1500 engine hours, the parts to have aboard, and the fluids the manual specifies.
Put the Beta Marine Beta 20 schedule on your boat
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Track this engine freeImportant service notice
This page is a general maintenance planning guide for yacht operations. It is not an OEM service manual and does not override the official Beta Marine manual, warranty terms, class requirements, flag-state obligations, oil analysis recommendations, or dealer instructions for your exact engine serial number and installation.
The intervals, tasks and fluid specifications below are taken from Beta Marine Operator's Manual, Beta 10 to 115T heat exchanger cooled engines, Rev 46 (02/2026). Schedule: p. 50-51. Open the Beta Marine document
Where this engine is used
Beta Marine uses one schedule for its heat-exchanger-cooled engines from the Beta 10 to the Beta 115T. The 150-hour oil change applies only to engines fitted with the optional shallow sump; standard-sump engines change oil every year or 250 hours, whichever comes first. Coolant is replaced every other year or 500 hours. A first service at 25 hours changes the gearbox oil and checks drive belt tension and all external fastenings.
- Auxiliary engine for small sailing yachts, sail-drive or shaft drive
- Propulsion for small motor sailers and narrowboats
- Replacement engine for older small auxiliaries
In yacht service, maintenance timing is shaped by more than the hour meter. Long idle periods, high-load passages, warm engine rooms, saltwater exposure, seasonal lay-up, charter schedules, fuel quality, and access constraints all affect when work should be planned. A good schedule therefore combines engine hours, calendar time, oil analysis, visual inspection, alarm history, and the captain's operating notes.
Daily checks
The manual lists these checks for each day the engine is used.
- Check engine oil level
- Check gearbox oil level
- Check coolant level
- Check battery fluid
- Check belt tension and alternator bolts
- Ensure sea/raw water inlet strainer is clear
- Drain off any water in fuel/water separator
- Run engine up to temperature and check for leaks
First service after 50 hours
The manual calls for this one-off service on a new engine after its first 50 hours of running. The regular intervals below apply from then on.
- Change engine lubricating oil
- Change oil filter
- Check for leaks from heat exchanger tube stack and tighten end cap bolts if required
- Drain off any water in fuel/water separator
Service interval checklist
Every 150 engine hours
Treat the 150-hour milestone as a planning checkpoint. Confirm parts availability, assign the work to a qualified marine engineer, and record findings with photos, meter readings, invoice references, and follow-up tasks.
- Change engine lubricating oil and filter (shallow sump engines only)
Parts to prepare
Engine oil, Oil filter
Every 250 engine hours or 12 months, whichever comes first
Treat the 250-hour milestone as a planning checkpoint. Confirm parts availability, assign the work to a qualified marine engineer, and record findings with photos, meter readings, invoice references, and follow-up tasks.
- Change engine lubricating oil (standard sump)
- Change lubricating oil filter
- Change fuel filter
- Check sea water pump impeller and change if worn
- Check wasting anode and replace when necessary
- Remove and clean heat exchanger tube stack and replace its rubber O-rings
- Check air cleaner element
- Check all external nuts, bolts and fastenings
Parts to prepare
Engine oil, Oil filter, Fuel filter, Sea water pump impeller, Anode (wasting zinc), Heat exchanger tube stack O-rings
Every 500 engine hours
Treat the 500-hour milestone as a planning checkpoint. Confirm parts availability, assign the work to a qualified marine engineer, and record findings with photos, meter readings, invoice references, and follow-up tasks.
- Change air cleaner element
Parts to prepare
Air cleaner element
Every 500 engine hours or 24 months, whichever comes first
Treat the 500-hour milestone as a planning checkpoint. Confirm parts availability, assign the work to a qualified marine engineer, and record findings with photos, meter readings, invoice references, and follow-up tasks.
- Replace engine coolant/antifreeze
Parts to prepare
Coolant (antifreeze)
Every 1500 engine hours
Treat the 1500-hour milestone as a planning checkpoint. Confirm parts availability, assign the work to a qualified marine engineer, and record findings with photos, meter readings, invoice references, and follow-up tasks.
- Check valve clearance
- Check injection nozzle pressure
Track these intervals from your hour meters
In HelmOps, the crew enter hour meter readings and each service turns due soon and then overdue as the engine runs, with alerts to the owner and captain. See how our yacht planned maintenance software tracks engine hours
Oil and coolant specifications
Specifications from Beta Marine Operator's Manual, Beta 10 to 115T heat exchanger cooled engines, Rev 46 (02/2026). Check the viscosity chart in your engine's manual against the temperatures you expect to operate in.
- Engine oil
- Minimum API classification CF, multi-grade: SAE 15W/40 from -15 C upward, SAE 10W/30 for -30 C to 0 C. Mineral or semi-synthetic (no more than 30% synthetic) only; no additives and no fully synthetic oil.
- Coolant
- Mono ethylene glycol based extended-life antifreeze mixed 30% to 50% with fresh water; do not exceed 50%.
- Gearbox oil
- Depends on gearbox model: ATF for TMC40, TMC60/A, TMC260, ZF 25/A, ZF 45/A, ZF 15 MIV, ZF 63 IV and PRM 60/90/125; oil for TM345/A, TM93/A, TM170/A and PRM 150 and up. First gearbox oil change after 25 hours.
Engine running-hours log
Log meter readings for each engine, see the hours between entries and track hour-based services. A service turns amber with 50 hours or less to go and red when it is due.
Crew planning notes
The safest way to manage Beta Marine Beta 20 maintenance is to keep the next service visible in the vessel's operating rhythm. The chief engineer or captain should review the hour meter at each handover, compare it with the planned route, and reserve workshop time before a busy charter period begins. For twin-engine yachts, keep port and starboard records separate even when both engines are serviced on the same day.
Parts planning matters as much as the checklist. Filters, belts, coolant, zinc anodes, impellers, approved oils, gaskets, and specialist tooling may not be available at short notice in smaller cruising grounds. For larger Beta Marine installations, diagnostic access and authorised technician availability can become the real constraint. Captains should therefore turn each interval into a task list with owner approval status, purchasing notes, supplier details, and target dates.
Service evidence should be complete enough for a future buyer, surveyor, manager, insurer, or flag-state inspector to understand what happened. A useful record includes the date, engine hours, engineer name, parts used, fluid quantities, photographs, oil analysis files where available, defects found, corrective actions, and the next due hour. When maintenance is tracked only in chat messages or paper invoices, it becomes difficult to prove that the vessel followed a disciplined programme.
Cooling-system work deserves special attention. Raw water strainers, impellers, heat exchangers, thermostats, anodes, hose clamps, and exhaust components all live in a harsh saltwater environment. A small restriction or worn impeller can become an overheating event under load. If the yacht is used seasonally, inspect the raw water side before the first serious passage rather than waiting for the next hour milestone.
Fuel quality also drives reliability. Water contamination, biological growth, blocked pre-filters, and air leaks can stop an otherwise healthy diesel engine. Each fuel filter service in the schedule is a good moment to compare filter condition with fuel history, tank cleaning records, and recent bunker locations. Any repeated filter restriction should be treated as an operational issue, not just a parts replacement.
Frequently asked questions
What are the service intervals for a Beta Marine Beta 20?
The Beta Marine manual cited on this page sets Beta Marine Beta 20 service work at 150, 250, 500, and 1500 engine hours. The tasks for each interval are listed above. Power ratings, model years and operating conditions can differ, so confirm the schedule against the manual for your engine's serial number.
What oil specification should I use for a Beta Marine Beta 20?
The Beta Marine manual cited on this page specifies Minimum API classification CF, multi-grade: SAE 15W/40 from -15 C upward, SAE 10W/30 for -30 C to 0 C. Mineral or semi-synthetic (no more than 30% synthetic) only; no additives and no fully synthetic oil. Choose the viscosity for the temperatures you operate in, and if your manual specifies something different, confirm the grade with an authorised dealer or service provider.
When should the raw water impeller be replaced on a Beta Marine Beta 20?
Follow the seawater pump impeller interval in the Beta Marine schedule above. Replace it sooner if you find cracked or missing vanes, see overheating or weak raw water flow, or do not know when it was last changed.
Track Beta Marine Beta 20 maintenance in HelmOps
HelmOps helps captains and yacht managers turn engine-hour schedules into recurring tasks, service evidence, purchasing notes, and owner-ready maintenance records across the vessel.