Description

Yanmar YOM900, YOV900 Parts Catalog – 16 Pages of Factory Part Numbers

I have spent 28 years turning bolts in San Antonio, and the one thing that burns my tail is watching a guy spend an hour cross-referencing an aftermarket parts list that doesn’t even match the casting numbers on the block. This Yanmar YOM900, YOV900 Parts Catalog is the real deal – factory-issued, 16 pages, and packed with the exact part numbers you need to order the right pieces the first time. No “compatible with” nonsense. You get the OEM code, the quantity, and the service stock designation so you know whether it’s a repair part or a service stock item. That alone saves you a return trip to the dealer.

Cylinder Block Assembly Parts (Fig. 1)

Page 1 breaks down the cylinder block with 23 reference items. You get plugs in 3/8” and 1/2” sizes, main bearing sets, thrust metals, and main cap bolts – all with their specific part numbers. The manual uses a smart coding system: (R) for repair part, (S) for service stock, (T) for thickness, and (UP) for undercut part. That little (S) tells you the part is stocked for service, so you don’t waste time backordering a piece that’s sitting on a shelf. If you need a main bearing set, the part number 129901-01880 is right there. No guessing.

Gear Housing and Related Components (Fig. 2)

Page 2 covers the gear housing assembly – 69 line items including the housing assy, plugs, covers, gears, shafts, collars, and gaskets. Notice the reference to YOV9000 and YGV8000 at the top – this diagram applies across related models. The oil seal cover (part 118920-012600) and the crankshaft gear (115000-040400) are cataloged with exact quantities. When you’re rebuilding the front end of one of these Yanmar engines, having the right collar or gasket prevents oil leaks that take hours to chase down later.

Why a 16-Page Parts Catalog Beats a PDF From the Web

Every page is scanned from the original factory print. The resolution is good enough to read the (R), (S), and (P) codes clearly. Compare that to a third-party compilation where someone retyped part numbers and introduced typos – I’ve seen 129901-01700 become 12996I-01700 and then you get the wrong block. This catalog preserves the original layout, so the reference numbers match the diagrams without any cross-reference errors. 16 pages is short, but it’s dense. Each page covers a major assembly – cylinder block, gear housing, oil pump, cam chain – and you can find the exact hardware you need.

Yanmar YOM900 vs YOV900: What’s Covered?

The manual covers both the YOM900 and YOV900 models. The OCR excerpt shows YOV9000 and YGV8000 on page 2, indicating that the gear housing section also applies to those variants. If you’re working on a YOM900 with a different serial number range, check the part numbers carefully – the main bearing sets (129901-01880 and 129901-01890) are listed separately, likely for different undersizes. The “Remarks” column tells you if a part is a repair part (R) or service stock (S), so you know what to order for an overhaul versus a quick fix. No aftermarket catalog gives you that level of detail.

Source Authenticity: OEM vs Aftermarket Documentation

I have seen guys print out a generic parts diagram from a parts store website and then wonder why the bolt doesn’t fit. That’s because the aftermarket draws from memory, not from the factory casting. This catalog is an original Yanmar publication – you can see the copyright line on page 1: “(C)Copy Right YANMAR CO.,LTD. and YANMAR AGRICULTURAL EQUIPMENT CO.,LTD.” That’s the only source I trust for ordering engine internals. If you need to verify the part for a main cap bolt (129B01-01920), you look at that page, not some forum thread. For background on why OEM documentation matters in the Automotive Industry Overview, you’ll see that precision in parts sourcing directly affects reliability. And if you’re into heavy equipment, the Automotive Industry Overview page covers similar standards.

FAQ

Is this a repair manual with step-by-step procedures?

No, this is a parts catalog. It gives you exploded diagrams and part numbers, not torque specs or removal steps. If you need repair instructions, look for the service manual.

How do I interpret the (R), (S), (T), (UP), (P) codes in the parts list?

Those codes are critical. (R) means repair part – only available as a replacement, not stocked for regular service. (S) means service stock – the part is kept in stock for routine maintenance. (T) indicates a thickness variant – usually for bearings or shims. (UP) means undercut part – a machined oversize for repair. (P) is pitting part – used when the original surface is pitted and needs a thicker coating. The manual lists these codes in the Remarks column next to each part number. For example, on page 1, the main bearing set 129901-01880 may have an (S) or (T) code; that tells you whether to order standard or undersize. Always check the code before calling the dealer – saves you a trip.

This catalog is a tool, not a coffee table book. 16 pages, but every page has 20–60 line items with part numbers, quantities, and service codes. If you are rebuilding a Yanmar YOM900 or YOV900 engine and you don’t have this document, you are working blind. Stop cross-referencing aftermarket garbage. Access the Factory Manual from AutoRepairManuals and keep it in your shop computer. Your torque wrench will thank you.