Beta Marine 50
50 HP · Heat exchanger (freshwater / indirect) cooled
The Beta Marine 50 (Beta 50) is a naturally aspirated four-cylinder marine diesel built on the Kubota V2203 base block, rated at 48.9 hp in Beta’s current operator manual. It uses indirect injection and heat-exchanger freshwater cooling, and is a popular repower for 38–45 ft cruising boats. It shares the medium-range service parts and the standard heat-exchanger maintenance schedule with the Beta 43 and 60. Below are its published specifications, the maintenance schedule, and the genuine Beta service-part numbers.
Specifications
| Engine type | 4-cylinder, naturally aspirated, indirect injection |
|---|---|
| Base engine | Kubota V2203 (BV2203) |
| Displacement | 2197 cc (134.1 cu in) |
| Bore × stroke | 87.0 × 92.4 mm (3.43 × 3.64 in) |
| Compression ratio | 22.0 : 1 |
| Maximum output | 48.9 HP (36.5 kW) @ 2800 rpm |
| Continuous output (US EPA) | 45.6 HP (34.0 kW) @ 2800 rpm |
| Maximum torque | 143.2 Nm @ 1600 rpm (90.0 ft·lb) |
| Fuel | Diesel (EN590 / ASTM D975) |
| Fuel injection pressure | 140 kgf/cm² (1991 psi) |
| Injection timing | 16.25° BTDC |
| Starting aid | Glow plug |
| Firing order | 1-3-4-2 |
| Valve clearance (cold) | 0.20 mm (0.0078 in) |
| Oil pressure at idle | ≥ 1.0 kgf/cm² (≥ 14.0 psi) |
| Oil pressure at rated rpm | 3.0–4.5 kgf/cm² (43–64 psi) |
| Engine oil capacity | 9.5 L (2.51 US gal) standard sump · 7.0 L (1.85 US gal) shallow sump |
| Coolant capacity | 7.4 L (1.69 US gal) |
| Recommended starter battery | 94 Ah, 620 CCA |
| Dry weight | 260 kg (574.0 lb) |
Maintenance schedule
Beta Marine's recommended service intervals for this engine. Most items are time-or-hours, whichever comes first — boats that sit still hit the calendar interval long before the hours.
Daily, or every 8 hours of running
- Check engine oil level
- Check gearbox oil level
- Check coolant level
- Check battery electrolyte level
- Check drive-belt tension and alternator mounting bolts
- Confirm the raw-water inlet strainer is clear
- Check stern-gland lubrication (if fitted)
- Drain any water from the fuel/water separator
- Run the engine to temperature and check for leaks
After the first 25 hours (running-in)
- Change gearbox lubricant (see the separate gearbox manual)
- Re-check all external nuts, bolts and fastenings — especially the flexible-mount lock nuts, since loose mounts cause vibration and shaft misalignment
- Re-check and adjust drive-belt tension
- Check and grease the ball-joint nyloc nuts on the gearbox and throttle-control levers
After the first 50 hours (running-in)
- Change engine oil
- Change the oil filter
- Check the heat-exchanger tube-stack end caps for leaks and tighten if needed
- Drain any water from the fuel/water separator
After 150 hours
- If a shallow sump is fitted, change the engine oil and filter at this point
Every year or 250 hours, whichever comes first
- Change engine oil (standard sump)
- Change the oil filter
- Check the air-cleaner element
- Inspect the raw-water pump impeller and replace if worn
- Check the sacrificial anode and replace as needed
- Remove and clean the heat-exchanger tube stack, renew its O-rings, refill with correctly mixed antifreeze, and check for leaks
- Lubricate the key-switch barrel
- Re-check external fastenings and the ball-joint nyloc nuts
- Change the fuel filter
Every 500 hours (in addition to the 250-hour service)
- Change the air-cleaner element
Every 1500 hours
- Check valve clearances
- Check injector nozzle pressure
Genuine service parts
Beta Marine part numbers for the routine service items on this engine. Several vary by build date or cooling type — check the note before ordering. Genuine parts are stocked by the Beta Marine dealer network; where a cross-reference is shown, an aftermarket equivalent is also available.
| Fuel filter (spin-on element) | 211-60210 / 211-02817 Heat-exchanger engines take 211-60210; keel-cooled engines take 211-02817. Confirm by your fuel-filter assembly or quote your engine’s Beta “K” number if unsure. |
|---|---|
| Engine oil filter | 211-70510/02 Spin-on oil-filter element for the BV2003 / BV2203 / BV2403 block. |
| Raw-water pump impeller kit | 207-09042-KIT Fits the Beta Marine (from June 2013) and Johnson (Sept 2009–June 2013) gear-driven pumps. Pre-Sept-2009 Jabsco pumps use impeller 207-80800 instead. |
| Sacrificial zinc anode (heat exchanger) | 209-61840 Pencil anode in the heat-exchanger end cap. Replace at least annually — more often in warm or brackish water. A wasted anode lets the tube stack corrode. |
| Heat-exchanger tube-stack O-rings | 212-07273 Pair (qty 2) for the 3-bolt end caps — renew whenever the tube stack is pulled for cleaning. Single-bolt end caps use 209-80110 instead. |
| Air-cleaner element | 211-09179 Plastic air-filter assembly from Jan 2014. Earlier builds: central wing-nut 211-08133 (Jan 2011–Jan 2014) or clamp-type 211-61831 (to Dec 2010). |
| Alternator drive belt | Varies by configuration Configuration-dependent — Beta marks this “check before ordering”. Common current options on 43/50/60: V-belt 214-80750 (from April 2011) or 6PK poly-vee 214-07037 (from Oct 2009), depending on the alternator. Confirm against your alternator and pulley set. |
| Thermostat | 600-05289 / 600-72450 Engines with a front-mounted stop solenoid take 600-05289; engines with a side-mounted solenoid take 600-72450. Gasket is 600-80490. Replace on-condition. |
| Fuel lift pump | 600-80870 / 600-00633 Beta 43 & 60, and Beta 50 from July 2008, take 600-80870. Beta 50 to July 2008 takes 600-00633. Gasket is 600-00538. |
| Coolant pressure cap | 209-80130 Heat-exchanger filler / pressure cap. |
What owners watch
Raw-water impeller
The impeller is on the annual / 250-hour list, but it is worth inspecting more often — a shredded impeller can overheat the engine within minutes. Carry a spare (207-09042-KIT) and know where the raw-water pump is before you need it.
Heat-exchanger tube stack
The annual service includes pulling the tube stack, cleaning it, and renewing the rubber O-rings (212-07273). Defer it too long and the freshwater side scales up and cooling efficiency drops.
Thermostat varies by solenoid layout
This block was built with both front- and side-mounted stop solenoids, and the thermostat part number differs between them (600-05289 vs 600-72450). Check which your engine has before ordering a thermostat.
Fuel/water separator
Draining water from the separator is a daily-use item. On a boat that sits, water and diesel bug accumulate, and a watered or clogged filter is the most common no-start or power-loss cause on this engine.
Flexible engine-mount lock nuts
Beta calls out checking the flexible-mount lock nuts during running-in. Loose mounts throw off shaft alignment and cause vibration — worth a look any time you notice new vibration.
Manufacturer documentation
The figures above are summarised for quick reference. For the full operator's manual and illustrated parts list, go straight to Beta Marine — they keep the current revision, so you always get the right version for your engine.
Beta revises these documents — always download the current revision for your engine from their site.
Other engines in this range
Never miss a Beta Marine 50 service
Keeply builds your engine's maintenance schedule, tracks the hours, and reminds you before a service is due. Ask First Mate "what's overdue?" and get an answer from your own records. Free to start, no credit card.
Track your Beta Marine 50 →Specifications and service intervals are transcribed from Beta Marine’s heat-exchanger operator manual (OM-221-20031-HE, Rev 46) technical-data tables; service-part numbers are from Beta Marine’s Illustrated Parts List for the Beta 43–62T range (IPL-221-10913, Rev 26). The manual rates this engine at 48.9 hp (the model name "50" is nominal). Figures are for reference only — Beta revises both documents, and several parts vary by build date, cooling type and serial number. Always confirm against the current manual and your engine’s own documentation before ordering parts or carrying out service.