COMPLETE MANUFACTURER REFERENCE / 4 FAMILIES
Protect the machine that depends on it.
Yanmar's compact-engine and equipment families reward careful identification. A YPFR, a YPES and a YPD-MP are distinct source names; avoid deciding compatibility by appearance or by a partial MP number alone.
Have a pump identification plate, an engine model or a photograph? You have enough to start the conversation. We will help review the information and discuss available service or parts options for the exact component, without assuming every model is serviceable.
More identification insights and technical background
Yanmar diesel equipment often keeps construction, agriculture, marine and standby applications going. The YPFR, YPES, YPD-MP/MP2/MP4 and OPE identifiers in this reference may help match a pump to an engine.
Which Yanmar injection design is fitted?
Engine serial numbers and full pump codes are especially valuable on compact equipment, where slight variations may affect mounting, delivery and control.
Pump families in our reference
Search this family list: YPFR, YPES, YPD-MP (MP2 / MP4), OPE.
Yanmar history, identification and practical service questions
From a Small Shop in Osaka to Your Back Forty
Magokichi Yamaoka founded the company in Osaka in March 1912. In 1933 it launched the HB, which Yanmar calls the world’s first practical small diesel engine. That idea, a real diesel in a small package, is still the whole Yanmar story.
Did You Know? The Yanmar name nods to the yanma, a big Japanese dragonfly, with a bit of the founder’s own name, Yamaoka, mixed in. Fitting for an engine maker known for small, tough and everywhere.
For American owners, Yanmar shows up in three places:
- Compact tractors. Yanmar has long supplied engines to other brands, including John Deere, so check the engine label even if the hood says something else.
- Mini excavators and compact equipment. Yanmar builds its own mini excavators, and its TNV engines power skid steers, loaders and generator sets.
- Marine. Yanmar is a familiar name in sailboat auxiliaries and small workboats, where water in the fuel is enemy number one.
We test, rebuild and calibrate Yanmar pumps from all three worlds.
How to Identify a Yanmar Pump
Start with the engine model, then the pump number. The engine label tells you the family, like 3TNV88 or 4TNV84, and the pump carries its own Yanmar number.
| Identification clue | What to check |
|---|---|
| Pump number 729xxx-51xxx on a 3TNV84, 3TNV88, 4TNV84 or 4TNV88 | Yanmar MP distributor-type pump |
| A small single-element pump on a compact engine | Compare the complete pump and engine number against YPFR and other engine-specific listings |
Owner’s Tip: On a boat or a machine that sits, drain the water separator and check the filter bowl before you blame the pump. Then bleed the system the way your engine manual describes. A surprising number of "bad pumps" are really water, air or a clogged filter.
Discussing Yanmar components by mail
Send the engine model, complete pump number and photos. We can confirm whether your exact Yanmar-related component is a candidate for inspection.
Choosing the right pump reference for a Yanmar engine
Yanmar engines are widely used in equipment sold under other brands, which makes the engine data plate especially useful. A compact tractor’s decal or an excavator’s model number may not identify the exact fuel equipment fitted to the engine. Full Yanmar engine and pump numbers help distinguish units that may vary in mounting, control linkage or delivery characteristics.
When reviewing a Yanmar component, describe the machine’s duty as well as the symptom. Long storage in a generator or seasonal machine can introduce fuel-quality and sticking concerns. A compact excavator that loses power under hydraulic load may call for supply-side and governor checks. A marine auxiliary that starts poorly after winter storage raises yet another set of useful questions. The pump is one part of the system, not the only possible cause.
The Yanmar MP guide, YPES guide and YPFR reference offer a closer look at selected designations. For engine-specific details, see our Yanmar TNV guide.
Ask About Yanmar Pump Service: Start your repair inquiry
How mail-in service works | Browse pump families
Related pump-family guides
Additional detailed family guides
- YPES: identification, applications and repair questions
- YPD-MP (MP2 / MP4): identification, applications and repair questions
Family-by-family guidance
These are all the pump families named under YANMAR in DCT’s source register. Each note focuses on getting the component identified, separating a symptom from a diagnosis, and making the next step simpler. A family being listed is not a promise of available inventory, parts interchange or repair acceptance.
YANMAR / PUMP FAMILY
OPE
When you cannot find your pump in a typical online catalog, you have not reached a dead end; you have reached the point where identification matters most.
The OPE label deserves to be read in full. Keep any suffix, drive-end marking and engine-manufacturer number with the OPE reference. Names reused across decades and applications are not proof that two assemblies have the same settings or parts.
The family name is a useful signpost, not a complete technical specification. On less-common systems, a wrong assumption can create more downtime than the original fuel complaint.
Before you remove, replace or ship it: Send the clearest photo of the complete pump, every visible number, the engine/equipment serial and a short description of symptoms before discussing parts or shipping.
Explore OPE: identification, symptoms and next steps
Before you decide it needs a pump
This reference often appears in older or specialist equipment where an exact number is more valuable than a broad internet search. Model-family naming alone is not a reliable service specification.
When compact industrial, marine and agricultural diesel engines has to earn its keep, the first good result is a reliable identity for the OPE unit. That saves time chasing an attractive but potentially incompatible replacement.
Identify this YANMAR family confidently
Because “OPE” is a short designation, include the YANMAR maker name in searches and keep the entire identification plate in any inquiry. A short letter code is easily mistaken for unrelated equipment terminology.
Why the application matters: In compact industrial, marine and agricultural diesel engines, the engine or machine serial reference may be needed to locate the correct fuel-system specification. Keep that identification with any part photos and diagnostic notes.
The observations that help the most
- Take a sharp close-up of all numbers and a wider photograph showing the complete housing, drive and controls.
- Record the equipment make, engine model and serial, plus any manual or historical parts-book number.
- Describe the complaint, storage history and any previous modifications or substituted parts.
Safety and accuracy: Avoid ordering a similarly named pump or assuming service acceptance until the exact assembly has been identified.
Three questions worth asking before authorizing work
- Is the identification from the original plate or an old parts invoice?
- Has the pump been replaced, rebuilt or re-tagged previously?
- Which engine number can be used to verify the correct configuration?
From concern to a practical next step
Start with what the operator noticed, add the facts an independent shop has already measured, and photograph the full unit plus every number. DCT can then discuss whether identification help, additional engine-level testing, a supported component evaluation or a parts inquiry is the appropriate next conversation. The exact work and receiving location are confirmed before anything is shipped.
See the simple three-step mail-in process · Search published identification references · Resources for repair shops
YANMAR / PUMP FAMILY
YPD-MP (MP2 / MP4)
An obscure pump designation is worth preserving instead of replacing with a guess from an unrelated model.
The YPD-MP (MP2 / MP4) label deserves to be read in full. Keep any suffix, drive-end marking and engine-manufacturer number with the YPD-MP reference. Names reused across decades and applications are not proof that two assemblies have the same settings or parts.
The family name is a useful signpost, not a complete technical specification. On less-common systems, a wrong assumption can create more downtime than the original fuel complaint.
Before you remove, replace or ship it: Send the clearest photo of the complete pump, every visible number, the engine/equipment serial and a short description of symptoms before discussing parts or shipping.
Read the YPD-MP (MP2 / MP4) technical guide Ask DCT about this family
YANMAR / PUMP FAMILY
YPES
A rare part number can be the difference between a clear answer and days of searching the wrong family.
The YPES label deserves to be read in full. Keep any suffix, drive-end marking and engine-manufacturer number with the YPES reference. Names reused across decades and applications are not proof that two assemblies have the same settings or parts.
The family name is a useful signpost, not a complete technical specification. On less-common systems, a wrong assumption can create more downtime than the original fuel complaint.
Before you remove, replace or ship it: Send the clearest photo of the complete pump, every visible number, the engine/equipment serial and a short description of symptoms before discussing parts or shipping.
YANMAR / PUMP FAMILY
YPFR
The component may look simple on a bench, but its original position and engine arrangement are not disposable details.
The YPFR label deserves to be read in full. Keep any suffix, drive-end marking and engine-manufacturer number with the YPFR reference. Names reused across decades and applications are not proof that two assemblies have the same settings or parts.
Individual pumping elements and unit-related systems demand special attention to the exact engine installation and adjustment arrangement. A familiar family word alone does not establish interchangeability.
Before you remove, replace or ship it: Photograph the installed layout, element numbering or configuration, fuel connections and any accessible part stamping. Follow the manufacturer procedure for safe removal and timing.
Your pump is not just a model number.
Tell us what it came from, how it has been acting, and any numbers you can read. Our specialists can review that information, discuss the next step for eligible components and provide the correct shipping destination before you send anything.
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