Yanmar · Inboard diesel
Yanmar 4LHA
The 4LHA is Yanmar’s 3.5-litre in-line four-cylinder marine diesel with turbocharger, intercooler and mechanical injection, catalogued from 1998 for planing motor boats with a shaft drive (Kanzaki, Hurth or ZF gearbox) or, as the Z versions, a MerCruiser Bravo sterndrive. It comes as the 4LHA-HTP (160 mhp), 4LHA-DTP (200 mhp) and 4LHA-STP (240 mhp), all rated at 3300 rpm; the sterndrive versions HTZP, DTZP and STZP and the E-suffix builds (HTE, DTE, STE and their Z versions) share the same parts catalogue. The three ratings differ in fuel filter, seawater pump and impeller, injectors and turbocharger, while the oil filter, alternator belt, thermostat, zinc anodes and most gaskets are common. It followed the 4LH-TE, HTE, DTE and STE of the early 1990s, from which many service parts carry over, and it is still on Yanmar’s product pages.
- Manuals & documents
- Wear parts & part numbers
- Service intervals
- Specifications
- Good to know
- On the marketplace
Manuals & documents
The links go straight to Yanmar, except the two parts catalogues, which the Yanmar specialist Léon Marine in Sète hosts. We host no manuals or drawings.
- Operation manual 4LHA-HTP, DTP, STP and HTZP, DTZP, STZP Operation manual yanmar.com · PDF · EN · DE · FR · ES
- Parts catalogue 4LHA-STE/STP, DTE/DTP, HTE/HTP incl. Z versions (0CR10-M47803EN, September 2014), hosted by the Yanmar specialist Léon Marine in Sète Parts catalogue leon-marine.com · PDF · EN
- Parts catalogue of the predecessor 4LH-TE/HTE/DTE/STE (0CR10-M32504EN, December 2014), hosted by the Yanmar specialist Léon Marine in Sète Parts catalogue leon-marine.com · PDF · EN
- Datasheet 4LHA-HTP / DTP / STP (April 2025) Spec sheet yanmar.com · PDF · EN
- Installation drawing 4LHA-STP with KMH50A gearbox Installation guide yanmar.com · PDF · EN
- 4LHA-STP product page (specs, drawings, manuals in 12 languages) Manual portal yanmar.com · EN
- 4LHA-HTP product page Product page yanmar.com · EN
- 4LHA-DTP product page Product page yanmar.com · EN
Wear parts & part numbers
| Part | OEM number | Also fits | Note |
|---|---|---|---|
| Engine oil filter | 127695-351501,2,3,4 | — | Same filter on every 4LHA, the Z sterndrive versions included; the 4LH catalogue also lists it for the 4LH-DTE and STE (the 4LH-TE and HTE take a different one). Diesel Parts Direct sells it as 127695-35150-12, which replaces the older 127695-35160. |
| Fuel filter (engine) | 121857-557101,2,3,5 | — | Spin-on main filter with water-separator bowl, only on the HT versions (4LHA-HTP, HTZP). Move the alarm switch in its bottom over to the new filter. The 4LH catalogue shows the same filter on the 4LH-TE and HTE. |
| Fuel filter (engine) | 41650-5023202,3,1 | — | Element (D72 × L90 mm, with O-ring and gasket) for the DT and ST versions and their Z versions: the 2014 parts catalogue lists 41650-502320 (added in November 2013), and the 4LH catalogue gives it for the 4LH-DTE and STE. The 4LHA operation manual still quotes element 41650-550800, and no source links the two numbers, so ask your dealer which one they supply for your engine. |
| Fuel pre-filter | 120324-557602,6 | — | Element for Yanmar’s optional fuel/water separator 120324-55750 (or -55751) on the DT and ST versions; the dealer also lists it for the 4LH-DTE/STE and the 6LY2/6LY2A. Only if that separator is fitted. |
| Air filter | 119195-188802,7replaces XN199611 | — | 58 mm element of the intake silencer, all 4LHA versions. Engines built before about April 2002 had a different silencer with inlet filter XN199611; the catalogue gives 119195-18880 as its replacement. |
| Raw water pump impeller | 120650-423102,8replaces 127610-42200 | — | DT and ST versions and their Z versions (pump 119175-42500). The catalogue moved from 127610-42200 to 120650-42310 in February 2007; Diesel Parts Direct, a Yanmar dealer, now supplies 127610-42270 as its replacement (one source). That dealer also lists the HTZE/HTZP, but Yanmar’s catalogue gives the HT versions their own pump and impeller (next row). |
| Raw water pump impeller | 123325-420212,3,9replaces 123325-42020 | — | HT versions (4LHA-HTP, HTZP) with pump 119171-42500/-42501. The same impeller fits every 4LH (TE, HTE, DTE, STE). |
| Pump cover O-ring | 119175-425702,10 | — | Cover O-ring of the DT/ST seawater pump 119175-42500. |
| Pump cover O-ring | 24321-0007002,3 | — | O-ring 1AG70.0 for the cover of the HT pump 119171-42500/-42501 and of every 4LH pump. |
| Water pump plate | 119175-425202 | — | Wear plate of the DT/ST pump 119175-42500. |
| Water pump plate | 119171-425402,3 | — | Wear plate of the HT pump 119171-42500/-42501; also on the 4LH-TE, HTE and DTE. |
| Pump seal kit | 129670-425602 | — | Mechanical seal of the DT/ST pump, which also has lip seal 119175-42580. Replace it if water keeps dripping from the drain hole under the pump. |
| Pump seal kit | 123472-420602,3 | — | Mechanical seal of the HT pump, which also has seal 123472-42150 (TC203508). |
| Raw water pump | 119175-425002,11 | — | Complete pump for the 4LHA-DTE/DTP and STE/STP and the Z versions DTZE/DTZP and STZE/STZP. |
| Raw water pump | 119171-425012replaces 119171-42500 | — | Complete pump for the HT versions; the catalogue’s later number for 119171-42500. |
| Alternator V-belt | 121850-422801,2,3,12 | — | A46 belt for alternator and coolant pump, all 4LHA versions and all 4LH engines. Tension: 8–10 mm deflection under thumb pressure. |
| Serpentine belt | 119175-265001,2,13 | — | 4PK1060 belt for the power-steering pump, only on the 4LHA-HTZP, DTZP and STZP (MerCruiser Bravo sterndrive). |
| Thermostat | 121850-498112,3,14replaces 121850-49810 | — | 71 °C, all 4LHA versions and all 4LH engines; the catalogue shows 121850-49811 replacing 121850-49810. Fitted with the two gaskets below. |
| Thermostat gasket | 121850-495402,3 | — | One of the two thermostat gaskets (used with 121850-49550); all 4LHA and 4LH. |
| Thermostat gasket | 121850-495502,3 | — | The second thermostat gasket (used with 121850-49540); all 4LHA and 4LH. |
| Anode (engine) | 119574-187901,2,15 | — | Zinc (1/2 × 1 in) in the intercooler, one on every 4LHA. The dealer lists the same zinc for the 6LY2/6LY2A, 6LYA and 6LP. |
| Anode (engine) | 119574-441501,2,16 | — | Zinc (1/2 in) for the engine oil cooler, two on every 4LHA, plus two in the heat exchanger of the DTP/DTZP and STP/STZP. The manual sizes the heat-exchanger zinc as 1/2 × 2 in under the same number. |
| Pressure cap | 129107-445902 | — | All 4LHA versions: on the exhaust-manifold filler of the DT/ST, on the cooler of the HT. |
| Exhaust mixing elbow | 119773-135002,17 | — | L-type mixing elbow of the shaft-drive 4LHA; on the Z sterndrive versions the catalogue changed to 119773-13501, marked fully interchangeable. The newest number, 119773-13510, rests on one dealer: Diesel Parts Direct sells it as the replacement for 119773-13501 and names the 4LHA-HTE and STP. A high-riser elbow is an option. |
| Exhaust elbow gasket | 119773-132502 | — | Mixing elbow gasket, all 4LHA versions; the Z sterndrive exhaust takes two. |
| Fuel injector | 719175-532002,18 | — | 4LHA-STE/STP and STZE/STZP only; four per engine. |
| Fuel injector | 719173-532002,19 | — | 4LHA-DTE/DTP and DTZE/DTZP only; four per engine. |
| Fuel injector | 719172-532002,20 | — | 4LHA-HTE/HTP and HTZE/HTZP only; four per engine. |
| Injector gasket | 129685-119302replaces 129470-11920 | — | Nozzle gasket of the DT and ST injectors, four per engine; the catalogue lists 129685-11930 as the interchangeable later part for 129470-11920. |
| Turbocharger | 119175-180311,2replaces 119175-18030 | — | IHI RHC61W turbocharger of the ST versions (4LHA-STP, STZP); 119175-18031 is the later number for 119175-18030. |
| Turbocharger | 119173-180412 | — | DT versions only (4LHA-DTP, DTZP). |
| Turbocharger | 119172-180302 | — | HT versions only (4LHA-HTP, HTZP). |
| Valve cover gasket | 119100-113202,21 | — | Rocker cover gasket, all 4LHA versions and all 4LH engines. |
| Gasket set | 719173-926002 | — | Optional set listed for all 4LHA versions, with head gasket 119174-01340 (1.3 mm) and the manifold, silencer, pump and cooler gaskets. |
Numbers checked against the sources below on 13 October 2026. Always confirm against your serial number and exact type before ordering.
Service intervals
| Task | Interval |
|---|---|
| First service | After the first 50 h: change engine oil and oil filter; the dealer adjusts the valve clearance and checks the injectors after the first 250 h1 |
| Engine oil change | Every 250 h or yearly, first time after 50 h1 |
| Oil filter | Every 250 h or yearly, first time after 50 h1 |
| Fuel filter | Every 250 h or yearly1 |
| Fuel pre-filter | Drain water from the fuel filter and the water separator every 50 h1 |
| Drain fuel tank | Every 50 h1 |
| Coolant change | Every 250 h or yearly1 |
| Anode | Check every 250 h or yearly; replace when less than half is left1 |
| Raw water impeller | Inspect every 1000 h or 4 years; replace every 2000 h even if it looks fine1 |
| Exhaust elbow check | Check daily1 |
| V-belt check | Check the tension every 500 h or 2 years; replace if damaged1 |
| Turbocharger wash | Every 250 h or yearly1 |
| Control cables | Adjust every 250 h or yearly1 |
| Battery | Check the electrolyte level every 50 h1 |
| Valve clearance | First at 250 h, then every 1000 h or 4 years (dealer)1 |
| Injectors | Pressure and spray pattern first at 250 h, then every 1000 h or 4 years; injection timing every 2000 h (dealer)1 |
| Cooling system | Clean the cooling passages and the oil cooler every 2000 h (dealer)1 |
From Yanmar’s 4LHA operation manual, which covers the HTP, DTP and STP and the HTZP, DTZP and STZP; hours or time, whichever comes first.
Specifications
| Cylinders | 4 in-line, four-stroke, water-cooled, direct injection1 |
|---|---|
| Aspiration | Turbocharger IHI RHC61W with water-cooled turbine housing, plus intercooler1 |
| Displacement | 3.455 l1 |
| Bore × stroke | 100 × 110 mm1 |
| Power | 4LHA-HTP: 118 kW (160 mhp); 4LHA-DTP: 147 kW (200 mhp); 4LHA-STP: 177 kW (240 mhp), all at 3300 rpm at the crankshaft (ISO 3046, fuel at 25 °C). Under ISO 8665 (fuel at 40 °C): 113 kW (154 mhp), 140 kW (190 mhp) and 169 kW (230 mhp). Continuous at 3100 rpm: 124, 158 and 190 mhp. The Z versions have the same ratings1 |
| Rated speed | 3300 rpm; no-load maximum 3700 ± 25 rpm1 |
| Idle speed | 750 ± 25 rpm1 |
| Injection | Mechanical: VE distributor pump on the HTP, in-line pump on the DTP and STP22 |
| Cooling | Fresh-water circuit with heat exchanger and centrifugal coolant pump; seawater pump with rubber impeller22 |
| Engine oil capacity | 13.0 l total, 10.0 l in the oil pan1 |
| Engine oil grade | API CD or better, SAE 15W-401 |
| Coolant capacity | 15 l in the engine plus 0.8 l in the sub-tank, per the spec table of the operation manual; the filling section of the same manual prints 1.5 l for the engine1 |
| Alternator | 12 V 60 A (80 A optional) in the operation manual; 12 V 80 A as standard on the 2025 datasheet1,22 |
| Starter motor | 12 V 2.5 kW1 |
| Battery | 12 V, 120 Ah recommended1 |
| Dry weight | Without gear. Operation manual: HTP 360 kg, DTP and STP 365 kg, Z sterndrive versions 385–388 kg; 2025 datasheet: HTP 342 kg, DTP/STP 365 kg1,22 |
| Gearbox | 2025 datasheet: Kanzaki KMH50A or KMH50V, or ZF68A (8° down angle). Older operation manual: Hurth HSW450A2 (HTP, DTP), Hurth HSW630A1 (STP) or Kanzaki KMH40A. The HTZP, DTZP and STZP drive a MerCruiser Bravo X-1, X-2 or X-3 sterndrive. Flywheel housing SAE #422,1 |
| Gearbox oil | KMH50A 1.8 l and KMH50V 5.4 l (API CF, SAE 30); ZF68A 4.0 l (ATF)22 |
| Belt tension | 8–10 mm deflection under thumb pressure midway along the belt1 |
| Years built | Parts catalogue from June 1998; the HTP, DTP and STP are still on Yanmar’s product pages, with a datasheet dated April 20252,22 |
Good to know
- Read the full model name on the engine plate before ordering. The HT engines (160 hp) have a spin-on fuel filter, their own seawater pump and impeller, injectors and turbo; the DT (200 hp) and ST (240 hp) take a cartridge fuel element and pump 119175-42500. A Z in the name means the sterndrive version, which adds a power-steering belt.2
- There are up to five zinc plugs: one in the intercooler, two in the oil cooler and, on the DTP and STP, two in the heat exchanger. Close the seacock first and replace a zinc once less than half of it is left.1
- Fit the seawater pump impeller with its vanes bent against the direction of rotation, and never turn the engine backwards by hand, or the vanes fold the wrong way. Yanmar wants the impeller replaced every 2000 h even if it still looks fine.1
- Do not overfill the oil: the surplus is blown out of the breather into the air intake. The oil cooler has its own drain plug, so open it as well when you change the oil through the dipstick tube.1
- Many service parts carry over from the older 4LH-TE/HTE/DTE/STE: the A46 V-belt, the 71 °C thermostat, the rocker cover gasket and the HT impeller fit both, and the 4LH-DTE and STE also share oil filter 127695-35150.3
On the marketplace
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Sources
- yanmar.com/marine/wp-content/uploads/2021/06/4LHA_E_H1.pdf
- leon-marine.com/wp-content/uploads/2021/02/4LHA-DTE-DTP-HTE-HTP-STE-STP.pdf
- leon-marine.com/wp-content/uploads/2021/02/4LH-HTE-4LH-HE-1.pdf
- dieselpartsdirect.com/ym1276953515012
- dieselpartsdirect.com/ym12185755710
- dieselpartsdirect.com/ym12032455760
- dieselpartsdirect.com/ym11919518880
- dieselpartsdirect.com/ym12761042270
- dieselpartsdirect.com/ym12332542021
- dieselpartsdirect.com/ym11917542570
- dieselpartsdirect.com/ym11917542500
- dieselpartsdirect.com/ym12185042280
- dieselpartsdirect.com/ym11917526500
- dieselpartsdirect.com/ym12185049811
- dieselpartsdirect.com/ym11957418790
- dieselpartsdirect.com/ym11957444150
- dieselpartsdirect.com/ym11977313510
- dieselpartsdirect.com/ym71917553200
- dieselpartsdirect.com/ym71917353200
- dieselpartsdirect.com/ym71917253200
- dieselpartsdirect.com/ym11910011320
- yanmar.com/marine/wp-content/uploads/2021/05/DS_4LHA-HTP-DTP-STP_A4_04-2025_HR.pdf
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