Yanmar · Inboard diesel

Yanmar 4JH4E / 4JH4AE

The 4JH4E and the 4JH4AE are the naturally aspirated four-cylinders of Yanmar’s JH4 generation: 2.19 l direct-injection diesels with mechanical fuel injection and fresh-water cooling, common as original engines and repowers in sailing yachts of roughly 36 to 45 ft. The 4JH4E, introduced in 2004 after the 4JH3E, came with the KM35P, KM35A2, KM4A or ZF30M gearbox or the SD40 saildrive; the 4JH4AE followed in 2007 with 39.6 kW (53.8 mhp) at 3000 rpm and the KM35P, KM35A2, KM4A1, ZF30M or the SD50 saildrive. It was replaced by the very similar 4JH5E; the turbocharged 4JH4-TE and 4JH4-HTE share its thermostat, coolant pump and impeller kit but are different engines. Most wear parts are the same on the 4JH4E and the 4JH4AE, but the fuel filter, the injectors and the fuel feed pump differ — check the engine plate before ordering.

Manuals & documents

The links go straight to Yanmar. We host no manuals or drawings — the manufacturer’s copy is the current one.

Wear parts & part numbers

PartOEM numberAlso fitsNote
Impeller kit (with gasket)129670-426102,3,4,5,6,7replaces 129670-42531Parts4Engines P4E4952013121614JH4E and 4JH4AE (dealers also list all 4JH4 and 4JH5); kit with impeller, cover O-ring and screws, replacing the loose impeller 129670-42531 of pump 129271-42501. 4JH4E engines built before June 2005 left the factory with pump 129271-42500 and impeller 129670-42530.
Pump cover O-ringX0506590-018,5,2,6—Cover O-ring of the sea-water pump, 4JH4AE; the catalogue prints 119773-42570 for the same ring. Included in impeller kit 129670-42610.
Water pump plate129670-425406,7,9,10—Wear plate behind the impeller of the seawater pump; 4JH4E and 4JH4AE. The manual asks for a check of the plate whenever the impeller is inspected.
Raw water pump cover plateX0146535-016,7,12,13replaces 129670-42520Parts4Engines P4E4952012941211End cover of the seawater pump; both catalogues list 129670-42520, which Diesel Parts Direct shows replaced by X0146535-01. Parts4Engines lists its cover plate with O-ring for the 4JH4E and 4JH4AE.
Impeller puller129671-921106,7,14,10—Puller A with M10 jack screw, named in the operation manual and listed in both tool kits; it grips the impeller by its M18 × 1.5 thread.
Raw water pump129271-425032,15,16,6,7,17replaces 129271-42502replaces 129271-42501Parts4Engines P4E4952013466415Gear-driven; 4JH4E, 4JH4AE and 4JH5E (4JH4E built before June 2005: 129271-42500). The catalogue number 129271-42501 became -42502, which Diesel Parts Direct now shows replaced by -42503. Mounting gasket 129150-01881 (see below).
Water pump gaskets129150-018816,7,18—Gasket between seawater pump and gear housing; 4JH4E and 4JH4AE. The catalogues keep this number for the pump; from June 2012 they list gasket 129C26-01890 only for the blanking cover 124240-01871 next to it.
Engine oil filter129150-351702,20,21,19,6,7replaces 129150-35153Parts4Engines (Bosch) P4E4952013129619Spin-on; 4JH4E and 4JH4AE, also 4JH3, 4JH5E and 4JH57/80/110.
Fuel filter (engine)119802-558102,22,23,6,24replaces 119802-55801—4JH4AE (and 4JH5E): spin-on filter; the catalogue number 119802-55801 has been replaced by -55810. The earlier 4JH4E takes the element in the next row instead — check the engine plate.
Fuel filter (engine)129470-5581026,25,27,7replaces 129470-55703replaces 129470-55702Parts4Engines (MANN) P4E49520134673254JH4E (pre-‘A’ engines): element in filter housing 129470-55601, the same as on the 4JH2 and 4JH3. The 4JH4E catalogue lists 129470-55702, from engine no. E04843 129470-55703. Not in the 4JH4AE catalogue.
Fuel pre-filter120324-557602,28,6—Element for the optional fuel/water separator 120324-55750 / -55751 (from April 2008); 4JH4AE and 4JH5E.
Fuel pre-filter41650-5023202,29,6,30—Element (72 × 90 mm) for the later separator 129670-55750 fitted from August 2011, with O-ring 24311-000120.
Fuel lift pump119225-521026,31,32—4JH4AE (and 4JH5E): separate fuel feed pump on bracket 129670-55010. Not on the 4JH4E.
Fuel lift pump129158-521017,33,34replaces 129158-52100—4JH4E: feed pump mounted on the injection pump, gasket 129155-52051; -52101 from engine no. E01543.
Air filter129271-123116,7,35replaces 129271-12310—Washable insert of the intake silencer, cleaned every 250 h; 4JH4AE and 4JH4E from June 2006 (earlier 4JH4E: 129271-12310). From November 2008 the catalogues also list the complete silencer 129271-12290 that contains it.
Alternator V-belt25152-0043002,37,38,36,6,7Parts4Engines (Gates) P4E4952013322336A43, drives alternator and coolant pump; 4JH4E, 4JH4AE and 4JH5E. The optional second alternator runs on an A38 belt 25132-003800.
Thermostat129470-498012,39,40,6,7—76.5 °C; 4JH4E, 4JH4AE, 4JH4-TE, 4JH4-HTE and 4JH5E — the same thermostat as on the 4JH2 and 4JH3.
Thermostat gasket129150-498112,41,42,6,7replaces 129470-49810—Replaced 129470-49810 from December 2009. The thermostat cover also uses gasket 129795-49551.
Coolant pump129271-420012,43,6,7—Belt-driven; 4JH4E, 4JH4AE, 4JH4-TE, 4JH4-HTE and 4JH5E. Mounting gasket 129486-42050. 4JH4E engines before no. E02737 were built with 129271-42000.
Pressure cap129673-441312,44,6,7replaces 129673-44130Parts4Engines P4E4952013532144Parts4Engines P4E4952012984444Cap of the heat exchanger (coolant tank) 129670-44910 / -44911; 4JH4E engines built before June 2005 had 129673-44130. Parts4Engines lists its zinc-plated (P4E49520135321) and stainless (P4E49520129844) caps for 4JH4E, 4JH4AE, 4JH4-TE/-HTE and 4JH5E.
Heat exchanger end-cap O-ring129670-441506,7,45,46—74.5 × 3 mm, two per engine for the heat exchanger end covers; 4JH4E and 4JH4AE. End-cover gasket 120322-33050, tube stack 129670-44460.
Exhaust mixing elbow129670-135612,47,6,7replaces 129670-13560—Interchangeable replacement for 129670-13560 since November 2007; 4JH4E, 4JH4AE, 4JH5E, also 4JH45/57 and 3JH4E/5E. Flange gasket 129472-18090. The catalogue also offers the alternative elbow 129470-13541 with water pipe 129670-49280.
Fuel injector729008-531002,6,48—4JH4AE only: complete injector, 4 per engine; nozzle 129008-53000, shim set 114250-53400 (119803-53400 from engine no. E07860). The 4JH4E takes a different injector (next row).
Fuel injector729602-531017,49—4JH4E only: complete injector, 4 per engine; nozzle 129602-53001, shim set 114250-53400 (119803-53400 from September 2007). Does not fit the 4JH4AE.
Valve cover gasket129601-113106,7,50—4JH4E and 4JH4AE; also part of gasket set 729670-92600.
Cylinder head gasket129407-013406,7,51—4JH4E and 4JH4AE (Diesel Parts Direct adds the 4JH5E); also part of gasket set 729670-92600.
Gasket set729670-926002,52,6,7—Complete set for the 4JH4E and the 4JH4AE (both catalogues list it), with head gasket 129407-01340, rocker cover gasket 129601-11310, manifold gasket 129470-12130 and the thermostat and pump gaskets.
Crankcase breather element119802-031306,7,53,10—Diaphragm of the crankcase breather in the rocker cover, with spring 119802-03141 and cover 119802-03121; 4JH4E and 4JH4AE. Yanmar has a dealer check the assembly every 1000 h.
Engine mount129470-083506,7,54replaces 129670-08351replaces 129670-08350—Flexible mount type 200, two per engine with the KM35P or KM35A2 gearbox (4JH4E and 4JH4AE). The catalogues list 129670-08350, from March 2009 -08351; Diesel Parts Direct shows that replaced by 129470-08350.
Engine mount129670-083416,7,55replaces 129670-08340—Flexible mount type 150, the other two of the four mounts with the KM35P or KM35A2 gearbox (4JH4E and 4JH4AE); -08341 since March 2009.
Engine mount129670-083906,7,56,57—Flexible mount assembly, two per engine with the SD50 saildrive or KM4A1 (4JH4AE) and the SD40 or KM4A (4JH4E), listed from December 2012 in place of mount 120149-08431, which Diesel Parts Direct still sells. The saildrive leg itself rests on shock absorber 196440-02380 (see our SD50/SD60 page).
Pressure switch124060-394526,7,59Parts4Engines P4E4952013329058Oil pressure switch (0.2 kg/cm²) for the warning lamp, not a gauge sender. From engine no. E07544 (4JH4AE) and September 2007 (4JH4E) the catalogues list the 0.5 kg/cm² switch 121252-39450 instead — check the serial number.
Starter motor129608-770106,7,60,61,10—Type S114-817A, 12 V 1.4 kW; 4JH4E and 4JH4AE. For cold starts the 4JH4AE has an intake air heater, 129120-77502 (optional on the 4JH4E, 129120-77501 until July 2006): turn the key to GLOW for about 15 seconds before starting.
Alternator119573-772016,7,62,10—12 V 80 A, standard on the 4JH4AE and on later 4JH4E; early 4JH4E had the 12 V 60 A 128271-77200 as standard, later as an option.

Numbers checked against the sources below on 23 October 2026. Always confirm against your serial number and exact type before ordering.

Service intervals

TaskInterval
First serviceAfter the first 50 h: drain the fuel tank, change engine oil, oil filter and gear oil (and the gear oil filter where fitted), adjust the V-belt, check and adjust the remote control cables; the dealer adjusts the valve clearance and the shaft alignment10
Engine oil changeEvery 250 h or yearly, first time after 50 h10
Oil filterEvery 250 h or yearly, first time after 50 h10
Gearbox oil changeFirst after 50 h, then every 250 h or yearly (KM and ZF gearboxes, with the gear oil filter where fitted; the SD50 saildrive has its own schedule)10
Fuel filterEvery 250 h or yearly10
Fuel pre-filterDrain the water separator every 50 h or monthly10
Drain fuel tankDrain water and sediment after the first 50 h, then every 250 h or yearly10
Air filterClean the intake silencer element every 250 h or yearly10
Raw water impellerInspect every 250 h or yearly; replace every 1000 h or 4 years even if it looks fine10
V-belt checkAdjust after the first 50 h, then check every 250 h or yearly10
V-belt replaceEvery 1000 h or every 4 years10
Coolant changeYearly; every 2 years with long-life coolant10
Exhaust elbow checkClean and inspect every 250 h or yearly; replace every 500 h or 2 years even if undamaged10
Hoses & clampsReplace the rubber fuel and water hoses every 2 years or 2000 h10
BatteryCheck the electrolyte level every 50 h or monthly10
Electrical connectionsCheck the wiring connectors every 250 h or yearly10
Valve clearanceFirst at 50 h, then every 1000 h or 4 years (dealer)10
InjectorsCheck injection timing and spray pattern every 1000 h or 4 years (dealer); for US EPA compliance Yanmar adds nozzle cleaning at 1500 h and a pressure and spray check at 3000 h10
Heat exchanger cleanClean and check the seawater passages every 1000 h or 4 years (dealer)10
Crankcase ventilationCheck the breather diaphragm assembly every 1000 h or 4 years (dealer)10
Control cablesCheck daily that they work; check and adjust after the first 50 h, then have a dealer check them every 1000 h or 4 years10
Engine alignmentPropeller shaft alignment after the first 50 h, then every 1000 h or 4 years (dealer)10
Storage / winterisingThe engine may stand idle for up to 6 months; for longer, ask a dealer. Before frost or a long lay-up drain the seawater circuit but not the coolant, drain water from the fuel filters, fill the tank or empty it, seal intake and exhaust and charge the battery once a month10

From Yanmar’s JH4 operation manual 0AJH4-G00103 (2008), which Yanmar does not put online but distributes through its dealers. It covers the 4JH4AE; for a 4JH4E built before 2007 ask a dealer for the matching edition. The schedule runs on hours or time, whichever comes first: 50 h or a month, 250 h or a year, 500 h or two years, 1000 h or four years. The SD50 saildrive has its own schedule (see our SD50/SD60 page). The later JH manual on yanmar.com covers the 4JH5E and the turbocharged 4JH4, not the 4JH4AE.

Specifications

Models4JH4E (from 2004) and 4JH4AE (from 2007), both naturally aspirated with 88 mm bore; the turbocharged 4JH4-TE and 4JH4-HTE have an 84 mm bore and 1.995 l7,6,10
Cylinders4, in-line, four-stroke, direct injection2,10,6
Bore × stroke88 × 90 mm (4JH4AE)10
Displacement2.19 l (4JH4AE)10
Power4JH4AE: 39.6 kW (53.8 mhp) at 3000 rpm maximum; 36.0 kW continuous at 2907 rpm10
InjectionMechanical injection pump with built-in mechanical governor: 729670-51320 on the 4JH4AE, 729670-51450 on the 4JH4E; engine-driven fuel feed pump, fuel/water separator optional2,6,7,63
Injection pressure19.6–20.6 MPa (4JH4AE)10
Injection timing4JH4AE: 5 ± 1° BTDC at fuel-stop power (FIR), 18 ± 1° BTDC at a plunger lift of 2.5 (FIT)10
Direction of rotationCrankshaft anticlockwise seen from the stern; propeller shaft clockwise ahead, seen from the stern10
CoolingFresh-water cooled with heat exchanger and coolant recovery tank; belt-driven coolant pump, gear-driven rubber-impeller sea-water pump2,6
Thermostat opens at76.5 °C2,6
Engine oil capacity5.5 l total, 5.0 l in the sump, 1.4 l between the dipstick marks with the engine level; 5.0 / 4.5 / 1.2 l at an 8° installation angle10
Engine oil gradeAPI CH-4 or higher; SAE 10W-30 or 15W-4010
Coolant capacity6.0 l in the engine plus 0.8 l in the recovery tank10
CoolantLong-life coolant (LLC) mixed with soft water to the maker’s ratio; never hard water, never mix types or colours10
FuelDiesel to EN 590, ASTM D975 No. 1-D/2-D or equivalent; cetane 45 or higher, sulphur max. 0.5 % (below 0.05 % preferred); biodiesel up to B5 only; no biocide10
Gearbox4JH4AE: KM35P or KM35A2 mechanical gearbox, KM4A1 angle drive, ZF30M or SD50 saildrive. 4JH4E: KM35P, KM35A2, KM4A, ZF30M or SD40 saildrive2,10,6,7
Gear ratioKM35P 2.36 or 2.61:1 ahead (3.16 astern); KM35A2 2.33 or 2.64:1 (3.06 astern); KM4A1 1.47, 2.14, 2.63 or 3.30:1; ZF30M 2.15 or 2.70:1; SD50 2.32:110,64
Gearbox oilKM35P 0.5 l, KM35A2 0.65 l, KM4A1 2.3 l of engine oil (API CD, SAE 20 or 30); ZF30M 1.1 l of ATF; SD50 2.1 l of SAE 90 or 80W-90 gear oil10
Alternator12 V 80 A (119573-77201); mount for an optional second alternator on an A38 belt2,10,6
Starter motor12 V 1.4 kW10
Belt tension8–10 mm deflection under finger pressure at mid-span10
Dry weight4JH4AE: 201 kg bare; 213 kg with KM35P, 214 kg with KM35A2, 229 kg with ZF30M, 230 kg with KM4A1, 241 kg with SD5010
Dimensions4JH4AE, length × width × height: 871 × 560 × 625 mm with KM35P, 864 mm long with KM35A2, 922 mm with KM4A1, 950 mm with ZF30M, 795 mm with SD5010
Emissions4JH4AE: certified by the US EPA as a marine compression-ignition engine above 37 kW10
Years built4JH4E introduced in January 2004, 4JH4AE in February 2007 (introduction dates in Yanmar’s parts catalogues); the catalogues record running changes until 20137,6,2

Good to know

  • Check the engine plate before ordering fuel-system parts: the 4JH4AE takes the spin-on filter 119802-55810, injectors 729008-53100 and the separate feed pump 119225-52102; the earlier 4JH4E takes the element 129470-55810 it shares with the 4JH2 and 4JH3, injectors 729602-53101 and the feed pump 129158-52101 on its injection pump.6,7,22,48,49
  • Quote the engine serial number when ordering: the 4JH4AE catalogue records running changes in November 2007 (mixing elbow), April 2008 and August 2011 (fuel/water separator), October 2008 (fuel filter bracket), December 2009 (thermostat gasket), March 2012 (oil cooler nut), June 2012 (sea-water pump gaskets) and July 2013 (coolant caps, silencer).2,6
  • Top up oil carefully: only 1.2–1.4 l separate the dipstick marks, and the fill depends on the installation angle — 5.5 l in total (5.0 l in the sump) with the engine level, 5.0 l (4.5 l) at 8°. Yanmar asks for API CH-4 or higher, SAE 10W-30 or 15W-40.10
  • Neither the 4JH4E nor the 4JH4AE catalogue lists a zinc anode on the engine (unlike Yanmar’s GM and YM engines). Corrosion protection sits on the saildrive leg or the propeller shaft, and the schedule relies on a dealer cleaning the seawater passages every 1000 h — so keep the raw-water strainer and the heat exchanger clean.6,7,2,10
  • Carry the impeller kit 129670-42610 and Yanmar’s puller 129671-92110. The manual wants the impeller replaced every 1000 h even if it looks fine; fit the new one with its M18 thread facing the cover so the puller can grip it next time; the kit brings a new cover O-ring.10,5,6
  • Long spells at idle, such as charging batteries at anchor, carbon up the injectors and rings and raise oil consumption. Yanmar asks not to idle longer than necessary and, after running at low speed and light load, to rev the engine in neutral from low to high speed a few times (five in the break-in instructions).10

Videos & how-tos

Links to YouTube, nothing embedded. The maker’s own channel comes first; the rest are channels we found clear and correct for this model.

Fitted in

Boats whose builder lists it as standard or optional equipment:

  • Najad 400 — Yanmar 4JH4-E (March 2005 specification: four cylinders, direct injection, fresh-water cooling, 39.6 kW (54 hp); the yard’s 2005 web page also gives 54 hp)

On the marketplace

Looking for a part for the Yanmar 4JH4E / 4JH4AE? Post a wanted ad in the app — it is free, it sits on the live map, and boaters nearby who have the part aboard can answer.

Got spares you no longer need? List them in a minute. No commission, ever.

Get the app

Sources

  1. parts4engines.com/products/yanmar-jh-series-raw-water-pump-impeller-kit
  2. mecanique-plaisance-finistere.com/yanmar/pdfmoteur/4jh4ae.pdf
  3. dieselpartsdirect.com/ym12967042610
  4. dieselpartsdirect.com/ym12967042531
  5. shop.marinedieselinc.com/products/129670-42610
  6. leon-marine.com/wp-content/uploads/2021/02/4JH4-AE.pdf
  7. leon-marine.com/wp-content/uploads/2021/02/4JH4-E.pdf
  8. dieselpartsdirect.com/ymx050659001
  9. dieselpartsdirect.com/ym12967042540
  10. Yanmar operation manual 0AJH4-G00103 (2008), via Yanmar dealers
  11. parts4engines.com/products/yanmar-4jh-raw-water-pump-cover-plate
  12. dieselpartsdirect.com/ym12967042520
  13. dieselpartsdirect.com/ymx014653501
  14. dieselpartsdirect.com/ym12967192110
  15. parts4engines.com/products/yanmar-4jh-series-raw-water-pump
  16. dieselpartsdirect.com/ym12927142502
  17. dieselpartsdirect.com/ym12927142503
  18. dieselpartsdirect.com/ym12915001881
  19. parts4engines.com/products/yanmar-4jh-oil-filter
  20. dieselpartsdirect.com/ym12915035170
  21. shop.marinedieselinc.com/products/129150-35170
  22. dieselpartsdirect.com/ym11980255810
  23. shop.marinedieselinc.com/products/119802-55810
  24. dieselpartsdirect.com/ym11980255801
  25. parts4engines.com/products/yanmar-4jh-fuel-filter
  26. dieselpartsdirect.com/ym12947055810
  27. shop.marinedieselinc.com/products/129470-55810
  28. dieselpartsdirect.com/ym12032455760
  29. dieselpartsdirect.com/ym41650502320
  30. shop.marinedieselinc.com/products/41650-502320
  31. dieselpartsdirect.com/ym11922552102
  32. shop.marinedieselinc.com/products/fuel-feed-pump-p-n-119225-52102
  33. shop.marinedieselinc.com/products/fuel-feed-pump-assembly-p-n-129158-52101
  34. dieselpartsdirect.com/ym12915852101
  35. dieselpartsdirect.com/ym12927112311
  36. parts4engines.com/products/yanmar-3jh-and-4jh-alternator-belts
  37. dieselpartsdirect.com/ym25152004300
  38. shop.marinedieselinc.com/products/25152-004300
  39. dieselpartsdirect.com/ym12947049801
  40. shop.marinedieselinc.com/products/129470-49801
  41. dieselpartsdirect.com/ym12915049811
  42. shop.marinedieselinc.com/products/129150-49811
  43. dieselpartsdirect.com/ym12927142001
  44. parts4engines.com/products/yanmar-3jh-and-4jh-series-header-tank-cap
  45. dieselpartsdirect.com/ym12967044150
  46. dieselpartsdirect.com/ym12032233050
  47. dieselpartsdirect.com/ym12967013561
  48. dieselpartsdirect.com/ym72900853100
  49. dieselpartsdirect.com/ym72960253101
  50. dieselpartsdirect.com/ym12960111310
  51. dieselpartsdirect.com/ym12940701340
  52. dieselpartsdirect.com/ym72967092600
  53. dieselpartsdirect.com/ym11980203130
  54. dieselpartsdirect.com/ym12947008350
  55. dieselpartsdirect.com/ym12967008341
  56. dieselpartsdirect.com/ym12967008390
  57. dieselpartsdirect.com/ym12014908431
  58. parts4engines.com/products/yanmar-oil-pressure-switch
  59. dieselpartsdirect.com/ym12406039452
  60. dieselpartsdirect.com/ym12960877010
  61. dieselpartsdirect.com/ym12912077502
  62. dieselpartsdirect.com/ym11957377201
  63. dieselpartsdirect.com/ym72967051320
  64. yanmar.com/media/global/com/product/marinepleasure/sailBoatPropulsion/operationmanualgear…

Yanmar is a trademark of its owner; boatparts.app is not affiliated with it. Part numbers are quoted for identification only. Spotted an error? Write to mail@boatparts.app.