Lombardini Marine · Inboard diesel

Lombardini LDW 1003 M

The LDW 1003 M is the three-cylinder engine of Lombardini Marine’s FOCS range: a 1028 cc indirect-injection diesel with pump-injector units, a belt-driven overhead camshaft and fresh-water cooling through a heat exchanger, built on the industrial LDW 1003 FOCS. Lombardini rated it at 30 hp (22.1 kW) until about 2016 and at 27 hp (19.5 kW) from 2017; a Technodrive TMC 40 gearbox was standard, with the TMC 60, the HBW 150 A or Lombardini’s own S-Drive saildrive (LDW 1003 SD) as options. Its siblings are the two-cylinder LDW 702 M and the four-cylinder LDW 1404 M, and Lombardini Marine is now part of Kohler (today Rehlko), which still lists the engine as the KDW 1003 M. Lombardini publishes no public marine parts catalogue, so this page has only three official part numbers and ten from one Italian dealer (Cirifalco), and no source ties an oil filter, fuel filter, timing belt or impeller number to the marine engine.

Manuals & documents
Wear parts & part numbers
Service intervals
Specifications
Good to know
On the marketplace

Manuals & documents

The links go to Lombardini Marine and to Kohler/Rehlko, which owns the brand today; the 2013 catalogue is an archived copy of Lombardini Marine’s own download. Lombardini publishes no public parts catalogue for its marine engines, so part numbers come from Kohler’s Global Parts Lookup or a Rehlko dealer. We host no manuals or drawings.

Owner manual LDW FOCS 502, 702, 1003 and 1404 M (ED0053031080, rev. 03) Operation manual lombardinimarine.com · PDF · EN · DE · FR · ES · IT · PT
Scheduled maintenance booklet with 36-month warranty coupons Servicing guide lombardinimarine.com · PDF · EN
S-Drive installation and maintenance handbook, FOCS and CHD Installation guide lombardinimarine.com · PDF · IT · EN
Fuel pre-filter and water separator kit: manual Servicing guide lombardinimarine.com · PDF · IT · EN
Workshop manual LDW FOCS 502 to 1404, industrial base engine (7th edition, rev. 06) Service manual iservice.lombardini.it · PDF · EN
iService documents LDW FOCS 702, 1003 and 1404 (industrial base engine) Service manual iservice.lombardini.it · EN
Global Parts Lookup: Kohler/Rehlko parts catalogues for diesel and marine engines Manual portal partnersportal.kohlerpower.it · EN
Rehlko dealer and service locator Manual portal engines.rehlko.com · EN
LDW 1003 M product page (specs, accessories, downloads) Product page lombardinimarine.com · EN
LDW 1003 SD product page (saildrive version) Product page lombardinimarine.com · EN
LDW/KDW marine propulsion brochure (502 to 1404 M and SD) Brochure lombardinimarine.com · PDF · EN
Lombardini Marine catalogue 2013, FOCS and CHD (Italian) Archived maker page web.archive.org · PDF · IT

Wear parts & part numbers

Part	OEM number	Also fits	Note
Fuel pre-filter	`0060100500`¹	—	Lombardini Marine’s own pre-filter and water separator (36.5 micron) for its FOCS and CHD engines, fitted between tank and lift pump. Water-in-fuel warning lamp kit: 00M6200100.
Raw water pump	`ED0065845100-S`²	—	One dealer (Cirifalco): complete pump with 10-blade impeller for the LDW 502 M, 702 M, 1003 M and 1404 M. No source names a separate impeller number for this pump.
Alternator V-belt	`ED0024404510-S`³	—	One dealer (Cirifalco): poly-V belt 4PK710, sold as the FOCS ‘LDW Marine’ belt for the 702, 1003 and 1404. Engines still on a classic V-belt drive need a different belt, so check before ordering. The owner manual replaces it every 500 h.
Thermostat	`ED0091951240-S`⁴	—	One dealer (Cirifalco), short ref. 9195124: lists the LDW 702 M, 1003 M, 1204 M and 1404 M next to the industrial LDW/KDW engines. The same dealer sells a separate marine thermostat without any fitment, so confirm with the engine number.
Air filter	`ED0021751640-S`⁵	—	One dealer (Cirifalco), short ref. 2175164: lists the LDW 602 M, 702 M, 903 M and 1003 M and the industrial LDW/KDW 502 to 1003; not the 1404 M.
Heat exchanger end-cap O-ring	`ED0012002650-S`⁶	—	One dealer (Cirifalco), short ref. 1200265: the O-ring that seals the tube bundle, listed on the LDW 1404 M exchanger and also used on the marine LDW 502, 702 and 1003. The owner manual says to renew it if it looks worn when the tube bundle is cleaned.
Exhaust mixing elbow	`ED0095430690-S`⁷	—	One dealer (Cirifalco), old-style code 9543.069: water-injected exhaust riser for the LDW 502 M, 602 M, 702 M, 903 M, 1003 M, 1204 M and 1404 M.
Exhaust manifold gasket	`ED0044200700-S`⁸	—	One dealer (Cirifalco), short ref. 4420070: lists the LDW 602 M, 1003 M, 1204 M and 1404 M and the industrial FOCS/KDW engines.
Engine mount	`ED0086362650-S`⁹	—	One dealer (Cirifalco), short ref. 8636265: flexible mount for the inboard version, listed for the LDW FOCS 602 M, 702 M, 903 M, 1003 M, 1204 M and 1404 M. The S-Drive version has its own mounts (below).
Gasket set	`ED0082051090-S`¹⁰	—	One dealer (Cirifalco), short ref. 8205109: lower-engine (crankcase) gasket set for the LDW 903, 1003, 903 M, 1003 M and KDW 1003 up to engine number 32002 only. Later engines need a different set, so order by engine number.
Saildrive diaphragm	`0047755210`¹¹	—	Hull seal of the FOCS S-Drive (LDW 502, 702, 1003 and 1404 SD); the CHD S-Drive takes 0047756000. Lombardini says to renew it every 7 years; the moulding year is on its outer face.
Saildrive mount	`0086361250`¹¹	—	Three per engine on the LDW 702, 1003 and 1404 S-Drive (the 502 SD uses one 0086361250 and two 0086361500).
Saildrive anode	`ED0062500320-S`^12,11	—	One dealer (Cirifalco): zinc anode in two halves for the S-Drive of the LDW 502 M, 702 M, 1003 M and 1404 M (and KDW 2204 M-MP). Lombardini’s S-Drive handbook says to replace it at 50 % wear and at least once a year.

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	First 50 h below 70 % of full power, then change engine oil, oil filter and fuel filter¹³
Engine oil change	First after 50 h, then every 125 h (every 60 h with an oil below the specified grade)¹³
Oil filter	Every 125 h, first time after 50 h¹³
Fuel filter	Every 250 h, first time after 50 h¹³
Raw water impeller	Inspect every 250 h, or every 12 months on a little-used engine; the warranty coupon booklet replaces it every 125 h or 12 months^13,14
Anode	Check every 250 h, or every 3 months on a little-used engine (coupon booklet: every 4 months); renew with a genuine plug tightened to 15 Nm^13,14
V-belt check	Check the tension every 250 h¹³
V-belt replace	Every 500 h¹³
Hoses & clamps	Check the cooling and fuel hoses every 250 h¹³
Heat exchanger clean	Clean the tube bundle every 500 h (coupon booklet: 500 h or 24 months)^13,14
Coolant change	Replace every 500 h (coupon booklet: 500 h or 24 months)^13,14
Gearbox oil change	Every 500 h, first time after 50 h¹³
Valve clearance	Every 500 h, by a Lombardini workshop (coupon booklet: 1000 h or 24 months)^13,14
Injectors	Check the setting and clean every 2500 h, by a Lombardini workshop (coupon booklet: 1000 h or 24 months)^13,14
Timing belt	Every 5000 h, or every 4 years on a little-used engine; always renew a belt that has been removed (coupon booklet: 2500 h)^13,14
Saildrive oil	Every 250 h or yearly¹¹
Saildrive diaphragm	Every 7 years, sooner if the insurer asks (for example every 5 years)¹¹
Saildrive anode	Inspect regularly; replace at 50 % wear and at least once a year¹¹

From Lombardini Marine’s owner manual for the LDW FOCS 502 to 1404 M (ED0053031080, rev. 03); the S-Drive rows come from the S-Drive handbook. Lombardini Marine’s 36-month warranty coupon booklet differs in places (impeller renewed every 125 h or 12 months, timing belt at 2500 h, valves and injectors at 1000 h or 24 months), and each of those rows gives both figures. The manual leaves valve clearance and injectors to a Lombardini workshop.

Specifications

Type	Marinised Lombardini LDW 1003 FOCS (today Kohler/Rehlko KDW 1003), four-stroke diesel^15,16
Cylinders	3 in line¹⁶
Displacement	1028 cc¹³
Bore × stroke	75 × 77.6 mm¹³
Compression ratio	22.8:1¹⁶
Injection	Indirect, with pump-injector units; overhead camshaft driven by a toothed belt¹⁶
Power	27 hp (19.5 kW) at 3600 rpm, the EU RCD Stage 2 rating listed since 2017 · earlier literature (2001–2016): 30 hp (22.1 kW) maximum, 28 hp (20.6 kW) at the propeller shaft^16,17
Rated speed	3600 rpm¹⁶
Cooling	Fresh water through a heat exchanger with zinc anode, self-priming sea-water pump, water-injected stainless steel exhaust elbow¹⁶
Engine oil capacity	2.4 l with filter, to the MAX mark; the marine owner manual prints 2.4 kg, the industrial FOCS workshop manual 2.4 l; the amount varies with the installation angle^13,18
Engine oil grade	SAE 5W-40 synthetic; API SJ/CF-4, ACEA A3/B3 and E5/E7 (owner manual 2018/2021)¹³
Coolant capacity	3 l¹³
Coolant	50 % demineralised water and 50 % low-silicate ethylene-glycol coolant (OAT or HOAT)¹³
Gearbox	Technodrive TMC 40 as standard, 2:1 for a right-hand propeller (other ratios on request); TMC 60 optional; the 2002 price list also offered the HBW 150 A¹⁷
Gear oil capacity	0.2 kg as printed in the owner manual; oil grade per the gearbox maker’s documentation¹³
Saildrive	LDW 1003 SD with Lombardini S-Drive: helical gears, 2.18:1, left- or right-hand propeller; 141 kg dry¹⁹
Drive oil capacity	S-Drive: 3.75–3.85 l, checked with the dipstick screwed fully in¹¹
Drive oil	SAE 15W-40, API CD (MIL-L-2104C)¹¹
Dry weight	110 kg with reversing gear (owner manual); 115 kg with TMC 40 (product page)^13,16
Dimensions	Length 643 mm, width 488 mm, height 522 mm (with TMC 40)¹⁶
Alternator	120 A on later engines (2013 catalogue, 2017 and 2021 price lists); 65 A in the 2002 price list, 80 A in 2006; a second 120 A alternator was available as a kit²⁰
Valve clearance (cold)	0.20 mm intake and exhaust (0.15 mm with Lombardini’s alternative method B); industrial FOCS workshop manual, a job for a Lombardini workshop¹⁸
Injection pressure	140–155 bar for the current pump-injector unit, 130–145 bar for the old type (industrial FOCS workshop manual)¹⁸
Thermostat opens at	83–87 °C, 7 mm lift at 94 °C (industrial FOCS workshop manual)¹⁸
Belt tension	Alternator belt: no more than 1 cm deflection under about 10 kg thumb pressure; 35–40 kg (360–410 N) with a tension gauge¹³
Battery	12 V 100 Ah, 800 CCA above −15 °C; 110 Ah / 950 CCA down to −25 °C¹³
Max. installation angle	15° as installed, 20° while running¹³
Fuel	Diesel to EN 590 or ASTM D975, cetane number 45 or more; biodiesel blends up to B10 (EN 14214 / ASTM D6751)¹³
Years built	Since 2001 (on Lombardini Marine’s website by May 2001); still listed, as the KDW 1003 M since the 2021 price list^21,20

Good to know

No source ties an oil filter, fuel filter, timing belt or impeller number to the marine LDW 1003 M; the dealer listings for these parts name only the industrial engine or no engine at all. Look them up by engine number in Kohler’s Global Parts Lookup, or ask a Rehlko dealer through the dealer locator.^22,23
Order parts with the model and serial number from the engine plate; Lombardini Marine asks for both, and some parts changed at a given engine number. The engine core is the industrial LDW 1003 FOCS, but sea-water pump, heat exchanger, exhaust riser, belts, mounts and air filter are marine items, so ask for the ‘M’ fitment, not just ‘1003’.^13,15
The camshaft runs on a toothed belt. If a boat comes with no record of a belt change, renew it before relying on the engine; Lombardini says a belt that has been taken off must always be replaced.¹³
Fit a water-separating pre-filter of 30 to 40 micron between tank and lift pump, as Lombardini Marine recommends; without one, water and dirt go straight to the pump-injector units.¹
Bleed the fuel system with the hand lever on the lift pump and the bleed screw on the filter bracket; Lombardini warns against using the starter motor to bleed it.¹³
Warm the engine up at 1300 to 1500 rpm rather than at idle. If no water comes out of the exhaust, raise the speed briefly to 1800 to 2000 rpm to help the sea-water pump prime.¹³

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Sources

Lombardini Marine 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.