Yanmar · Inboard diesel

Yanmar 3QM30

The 3QM30 is Yanmar’s three-cylinder sailboat auxiliary of about 33 hp from the late 1970s, built from about 1976 to 1980 according to the Yanmar dealer Torresen Marine; the GM series (3GM30) replaced it around 1980. This page also covers the 3QM30F, the 3QM30H and the two-cylinder 2QM20: they share one parts catalogue with the 2QM and 3QM and the same raw-water pump and impeller, oil filter, fuel and air filter, alternator belt and zincs, while the later Y versions (2QM20Y, 3QM30Y) have a catalogue of their own. The standard engine is cooled directly with seawater; the catalogue also lists a fresh-water circuit with heat exchanger, apparently that of the 3QM30F. Yanmar no longer publishes manuals for the QM series and refers owners to its dealers; the numbers here come from Yanmar’s own parts catalogue (2013 edition, hosted by the Yanmar specialist Léon Marine), Torresen’s archived copy of it and current dealer listings.

Manuals & documents
Wear parts & part numbers
Service intervals
Specifications
Good to know
Videos & how-tos
Fitted in
On the marketplace

Manuals & documents

Yanmar publishes no documents for the QM series and supplies them only through its dealers. The links go to Yanmar’s parts catalogue as hosted by a Yanmar specialist and to dealer pages and archives. We host no manuals or drawings.

Yanmar FAQ: how to get the manual of an engine no longer sold Manual portal yanmar.com · EN
Yanmar dealer & distributor locator (manuals, parts lists, genuine parts) Manual portal yanmar.com · EN
Parts catalogue 2QM, 2QM20, 3QM, 3QM30 (Yanmar 0CR10-M09109EN, May 2013 update), hosted by the Yanmar specialist Léon Marine in Sète Parts catalogue leon-marine.com · PDF · EN
Parts catalogue 2QM20 / 3QM30 (Yanmar Y00R0919, 35 groups) in the online catalogue of Yanmar dealer Torresen Marine, archived 2006 Parts catalogue web.archive.org · EN
3QM30 common service parts, list of Yanmar dealer Torresen Marine, archived 2001 Spares list web.archive.org · EN
Yanmar QM series parts at the UK dealer Parts4Engines: aftermarket oil and fuel filter, pencil anode and starter with fitment for the 3QM30 Spares list parts4engines.com · EN

Wear parts & part numbers

Part	OEM number	Also fits	Note
Raw water pump impeller	`124223-42092`^1,2,3,4,5replaces 124223-42091replaces 128296-42070	Sierra `18-8950`¹	Impeller of the 3QM30, 2QM20 and 2QM seawater pump. Yanmar’s catalogue prints 124223-42091, which Torresen refers to 128296-42070; current dealers sell 124223-42092, the Yanmar number Sierra gives for its 18-8950 for the 3QM30. The 3QM’s own pump takes 145410-46090. Compare with the old impeller before ordering.
Pump cover gasket	`124223-42110`^3,4,6,5,7	—	Gasket under the seawater pump cover, 3QM30 and 2QM20; fit a new one with every impeller change.
Raw water pump	`724770-42701`^3,4,5,8,9replaces 724770-42700	—	Complete seawater pump of the 3QM30, 2QM20 and 2QM; on the 3QM30 the -42701 version from engine no. 82252. The 3QM has its own pump (721390-42701). Its shaft seals are 124223-42080 (TC13×28×7) and 24422-153007 (TC15×30×7, formerly 124223-42160).
Thermostat	`105582-49200`^3,10,11,12	—	Thermostat of the seawater-cooled 3QM30; the same part as on the GM series (1GM10, 2GM20, 3GM30). The 2QM20 has 124770-49200, and engines with fresh-water cooling use 124790-49800.
Thermostat gasket	`121370-49160`^3,10,13	—	Gasket of the 3QM30 seawater thermostat; the 2QM20 uses 104211-49160.
Thermostat	`124790-49800`^3,14,15	—	Thermostat of the fresh-water circuit with heat exchanger, in its own housing; listed for all four QM engines.
Thermostat gasket	`124790-49760`^3,14,16	—	Gasket of the thermostat housing in the fresh-water circuit.
Heat exchanger end-cap O-ring	`24311-000950`^3,14,17	—	Fresh-water version: two O-rings (P95) seal the end covers of the heat exchanger.
Anode (engine)	`27210-200300`^{3,10,18,11,14,5,19,20}	—	Pencil zinc. The seawater-cooled 3QM30 has three, one in the cooling-water pipe and two in the cylinder head; the fresh-water version adds one in the heat exchanger cover. The same zinc as on GM, HM and the 2QM15.
Anode plug gasket	`123210-09310`^{3,10,18,6,5,21}	—	Seal ring for each zinc plug, one per anode.
Engine oil filter	`124085-35170`^22,23,24	—	Current dealer number for the 2QM20, 3QM30 and the 3HM engines. The old Yanmar catalogue prints 124550-35110 instead, and no supersession between the two was found — compare with the filter on your engine before ordering. Not the small filter of the 2QM15.
Fuel filter (engine)	`104500-55710`^{3,26,11,5,27,28}	Hengst `E486KP-D452`²⁵	Element of the engine-mounted fuel filter, 3QM30 and 2QM20; the same element as on the 2QM15 and the GM, HM and YM engines.
Fuel filter O-ring	`24341-000440`^3,26,5,29	—	O-ring of the filter cup; renew it with the element.
Fuel lift pump	`105582-52010`^3,26,30	—	Mechanical fuel feed pump on the engine; the same on all four QM engines (and on the 1GM10).
Fuel pump gasket	`121520-01851`^26,3,31replaces 124223-01850	—	Gasket under the fuel feed pump; the catalogue’s 124223-01850 has been replaced by 121520-01851.
Fuel injector	`724770-53100`^3,32	—	Complete injector, one per cylinder (three on the 3QM30, two on the 2QM20).
Injector nozzle	`124770-53000`^3,32,11	—	Nozzle of the injector, one per cylinder; Yanmar’s spare-parts kit for the 3QM30 contains three.
Injector gasket	`172100-53200`^3,32,6,33	—	Gasket of each injector (three on the 3QM30); also in Yanmar’s gasket set.
Air filter	`124770-12540`^3,34,5,35	—	Element of the intake silencer; the same on the 2QM15, 2QM20 and the 3HM engines.
Alternator V-belt	`25117-003151`^3,36,11,5,37replaces 124772-77350replaces 124772-42780	—	Alternator belt of the 3QM30 and 2QM20. Yanmar’s catalogue prints 124772-77350 (earlier 124772-42780), which has been replaced by 25117-003151.
Cylinder head gasket	`121370-01331`^3,11,6replaces 121370-01330	—	3QM30 head gasket, the -01331 version from December 1976. It is not in the gasket set 721370-92600, but Yanmar’s spare-parts kit contains it.
Valve cover gasket	`121370-11310`^3,18	—	Gasket of the 3QM30 head cover (bonnet); the two-cylinder engines use 124450-11310.
Exhaust manifold gasket	`121250-13520`^3,34,11	—	Three per engine on the 3QM30; also in Yanmar’s spare-parts kit.
Exhaust flange gasket	`124770-13170`^3,34,11	—	Two on the 3QM30, under the manifold end cover and under the exhaust connector flange; Yanmar’s spare-parts kit carries both.
Exhaust mixing elbow	`721370-13200`^3,34	—	Mixing elbow assembly of the 3QM30; the other QM engines have their own (724770-13200, 721390-13200). The catalogue also shows a second exhaust layout with elbow 124770-13550, now 104214-13521: compare with your engine before ordering.
Oil sump gasket	`121250-01751`^3,6replaces 121250-01750	—	Oil sump gasket of the three-cylinder engines; part of Yanmar’s gasket set.
Gasket set	`721370-92600`^3,6	—	Yanmar’s gasket set for the 3QM30 (the catalogue lists one set per engine). It does not contain the head gasket.
Spares kit	`721370-92500`^3,11	—	Yanmar’s spare-parts kit for the 3QM30, with head and manifold gaskets, piston rings, oil and fuel filter elements, impeller, thermostat, three zincs, oil pressure switch, three injector nozzles and the alternator belt, among others.
Pressure switch	`114250-39450`^11,3,38replaces 124160-39450	—	Oil pressure switch for the warning lamp; the catalogue’s 124160-39450 has been replaced by 114250-39450.
Starter motor	`121370-77010`^3,36	—	Starter S12-47 (12 V, 1.8 kW) of the 3QM30, 3QM and 2QM; the 2QM20 has its own starter (124770-77010).
Alternator	`121370-77200`^3,36	—	Generator LR135-31 (35 A), the same on all four QM engines.

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

Service intervals

Yanmar does not publish the QM-series operation manual online and supplies documents for engines it no longer sells only through its dealers, so this page lists no service intervals; ask a Yanmar dealer for the manual. Yanmar’s parts catalogue does show what to carry on board: the spare-parts kit in the parts list above.

Specifications

Cylinders	3 (2QM20: 2)⁵
Power	about 33 hp (dealer rating; Yanmar’s rating sheet is not online)⁵
Versions	3QM30, 3QM30F, 3QM30H and the two-cylinder 2QM20, all in Yanmar parts catalogue Y00R0919 (as cited by the dealer)³⁹
Models	One Yanmar parts catalogue for four engines: 2QM, 2QM20, 3QM and 3QM30; most service parts are shared, but the 3QM has its own seawater pump³
Cooling	Standard engine: direct seawater cooling, impeller pump and thermostat in the head. The catalogue also lists a closed fresh-water circuit with heat exchanger and coolant pump; the seawater impeller pump stays^3,10,14
Gearbox	Yanmar’s own clutch and reverse gear on the engine; KH-18A gearbox optional on the 3QM30 (KBW-10A on the 2QM20)^3,39
Gear ratio	3QM30: 2.20:1 (Yanmar’s own reverse gear on the engine); 2QM20: 2.20:1 or 3.21:1³
Starting	Electric starter, hand-start mechanism and a decompression lever on each cylinder^3,18,36
Starter motor	12 V, 1.8 kW^3,36
Alternator	35 A^3,36
Engine options	Listed as optional in the parts catalogue: remote control and an oil sump pump-out pump; the catalogue also has a seawater pump with an attached bilge pump^3,40
Years built	c. 1976–1980 (dealer data; no Yanmar source online)⁵

Good to know

Order the impeller by engine, not by series: the 3QM30 and 2QM20 take a larger impeller than the 2QM15, and early 3QM pumps that also drive a bilge pump use yet another one. Take the old impeller or the pump number to the dealer.^3,40,4
A seawater-cooled 3QM30 has three pencil zincs, one in the cooling-water pipe and two in the head: check them at every oil change and renew the seal rings with them.^3,11
Two oil filter numbers circulate for this engine, 124550-35110 in the old catalogue and 124085-35170 in current dealer lists. Take the old filter along or compare the dimensions before ordering.^22,24,23
The fuel filter element, its O-ring and the zincs are the same as on GM-series Yanmars and the air filter element is shared with the 3HM, so they are easy to find; engine-specific parts such as the pump, mixing elbow or gasket set may have to be ordered through a Yanmar dealer.^28,29,35,19
Write down the engine number before ordering: Yanmar’s catalogue changes parts at given engine numbers or dates, for example on the 3QM30 the seawater pump from engine no. 82252 (724770-42700 becomes -42701), the head gasket from December 1976 and the valve guides from November 1978.³
For the operation manual, ask a Yanmar dealer: Yanmar supplies documents for engines it no longer sells only through its dealer network.⁴¹

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.

Changing the impeller on a 3QM30H, with a look at the optional bilge-pump stage Video Ketching My 2nd Wind On SV ChopSticks · EN · 12 min
Rebuilding the seawater pump of a 3QM30H, part 2: reassembly and test Video Ketching My 2nd Wind On SV ChopSticks · EN · 12 min
3QM30 service in a Saga 27, part 1: zincs, fuel filter and impeller (Swedish) Video Stefan Bergman · SV · 40 min
3QM30 service, part 2: engine oil, oil filter, air filter, alternator belt and gearbox oil (Swedish) Video Stefan Bergman · SV · 46 min

Fitted in

Boats whose builder lists it as standard or optional equipment:

Tayana 37 — Yanmar 3QM30F (Late 1970s to 1987: standard engine of the dealer Southern Offshore Yachts and one of the two engines Ta Yang stocked in 1983 (about 30 hp, fresh-water cooled); the yard had six left in September 1987)

On the marketplace

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Sources

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