Description

Yanmar 4JH-DT, 4JH-DTZ Parts Catalog – 48 Pages of Factory Specs

I’ve been turning wrenches for 28 years. If there’s one thing that burns my time and your money, it’s ordering the wrong part because some aftermarket catalog had a fuzzy drawing and a wrong number. This 48-page OEM document from Yanmar fixes that. The Yanmar 4JH-DT, 4JH-DTZ Parts Catalog gives you factory exploded diagrams with authentic part numbers and interchangeability codes. You don’t guess – you order exactly what the engine was built with.

Engine Components Covered: 20 Exploded Views

This catalog breaks down the 4JH-DT and 4JH-DTZ into 20 separate figures. Each one is a clean, scan‑ready drawing with callouts. You get the cylinder block (Fig. 1), gear housing (Fig. 2), flywheel housing and oil sump (Fig. 3), cylinder head and bonnet (Fig. 4), suction manifold and air cleaner (Fig. 5), exhaust manifold and silencer (Fig. 6), camshaft and driving gear (Fig. 7), turbine (Fig. 8), crankshaft and piston (Fig. 9), lubrication oil system (Fig. 10) and line (Fig. 11), cooling water system (Fig. 12), fuel injection pump (Fig. 13), governor (Fig. 14), fuel injection valve (Fig. 15), fuel line (Fig. 16), starting motor (Fig. 17), generator (Fig. 18), electric parts (Fig. 19), and gasket set (Fig. 20). Every part you might need to order is laid out.

Decoding Interchangeability Marks

Parts get superseded. Yanmar marks each one with a letter code so you know if the new part fits your old engine or the other way around. The catalog spells it out: N means new part fits old, but old doesn’t fit new. Q is the reverse – old fits new, new doesn’t fit old. S is fully interchangeable both ways. R means no interchangeability at all – don’t waste money. W is a new addition, Z is discontinued, F means only interchangeable as a set, and K changes quantity. I’ve seen guys install a “close enough” part and watch it fail. This chart saves you that headache.

How to Read the Parts Catalog – Japanese and English

The first section is in Japanese, then repeated in English starting on page 2. Both explain the same structure: Ref. No., Level, Change Mark, Interchangeability Mark, Effective Machine No., and Remarks. If you’ve ever stared at a parts list and wondered what the column headers mean, this clears it up. The “Level” column uses dots to show where a sub‑part lives in the assembly hierarchy. Pay attention to the “Effective Machine No.” – that tells you the engine serial number range a part applies to. For example, under fuel injection pump (Fig. 29) you’ll see (A=E/#00185) meaning the part applies from engine number 00185 onward. Miss that and you’ll get a pump that doesn’t mount right.

Fuel Injection Pump Example – Fig. 29

Take a look at the boost compensator type on the 4JH-DT and 4JH-DTZ. The catalog lists two full injection pump assemblies: one with part number 769955-51320 and another 736955-51313, depending on the serial number range. Screws, gaskets, roller bearings, and retainer valves are all called out with quantities per engine. If you’re rebuilding that pump, you don’t need a micrometer – you need the exact OEM number. The page even notes optional specs up to E/#00155. That’s the kind of detail a shop manual leaves out.

Why a Factory Parts Catalog Beats Aftermarket Lists

Aftermarket catalogs often skip the interchangeability codes, combine parts across multiple models, or use a re‑numbered cross‑reference that might be wrong. This is a genuine Yanmar printed document – not a reprint or a scan of a scan. The 48 pages come from the original PDF with Japanese and English side‑by‑side. You get the same data a Yanmar dealer uses. For other related engine parts, check the Yanmar 4JH-DT Series Engine Parts Catalog 1997 or the Yanmar TL150 4JH Series Engine Parts Catalog. Also see the Yanmar 4JH-DT 4JH-DTZ 1997 Parts Catalog for a different publication year. For background on marine engine standards, refer to Automotive Industry Overview and the Automotive Industry Overview.

Does this catalog include bolt torque specs or service procedures?

No. It is a parts catalog, not a service manual. You get part numbers, drawings, and interchangeability data – not assembly torque values or repair steps.

How do I find the correct part number if my engine serial number is outside the listed ranges?

Check the Effective Machine No. column for each figure. If your engine number falls between two ranges, look for a “W” (new addition) or an “S” (interchangeable) part. If you still can’t match, note the closest figure and part description, then contact a Yanmar dealer with your engine model and serial. The catalog’s interchangeability marks (N, Q, S, R) tell you whether a later part will bolt on. For example, an “R” means no interchange – you need the exact original number. Always cross‑reference the Remarks column (U mark) for notes about special options or supersessions. That saved me three times last year on turbocharger gaskets alone.

If you’re working on a 4JH-DT or 4JH-DTZ and need to order parts without the back‑and‑forth of “is this the right one?”, this catalog is your answer. Stop wasting time on aftermarket lists that guess at numbers. Access the Factory Manual – the 48‑page OEM PDF that puts the right part number in your hand the first time.