Description

Yuchai YC4112ZQ, YC4112ZQ G0100, YC4112ZQ G0200, YC4112ZQ G0400, YC4112ZQ G0800 2002 Parts Catalog

I’ve been inside more diesel engines than I care to count, and the one thing that separates a job that stays together from one that comes back on a hook is using the right part numbers. Not the cross-reference from some aftermarket site that guesses. Not the handwritten note from the last guy. The numbers the factory stamped on the drawing. That’s what this 2002 Yuchai YC4112ZQ, YC4112ZQ G0100, YC4112ZQ G0200, YC4112ZQ G0400, YC4112ZQ G0800 2002 Parts Catalog delivers — the exact part callouts from Yuchai for the YC4112ZQ family of engines.

If you’ve ever ordered a crankshaft bearing set only to find the clearance is off because someone swapped a sub-variant, you know the pain. This catalog covers G0100, G0200, G0400, and G0800 variants. Each one has its own part numbers for the Cylinder block, Crankshaft, Camshaft, and Valve train. You cannot guess. You need the page.

Cylinder Block and Timing Gear Chamber: Where the Build Starts

Section 1 kicks off with the cylinder block assembly (G0100-1002000) on page 3. That’s the foundation. Section 2 covers the timing gear chamber parts (G0100-1002030) on page 5. Behind every oil leak or timing skip I’ve fixed, somebody grabbed the wrong gasket or gear set. This catalog shows the exact part number for every bolt, seal, and gear inside that chamber. You get the factory illustration and the callout. No guesswork.

Crankshaft, Flywheel, and Camshaft: OEM Part Numbers

Section 5 (B30-1005000) documents the crankshaft and flywheel assembly. Section 6 (B30-1006000) does the camshaft. These are the rotating assemblies you don’t want to misidentify. A 0.5 mm difference in bearing shell thickness can kill an engine in 50 hours. The catalog gives you the factory part code, the supercessions, and the assembly breakdown. Pair it with Yuchai YC6108G 2008 Parts Catalog – OEM Factory for larger displacement builds.

Valve Train and Cylinder Head Assembly

Section 3 (B30-1003000) covers the cylinder head and cover. Section 7 (B30-1007000) covers the valve train. Between those two sections you’ve got every rocker arm, pushrod, valve seat, and spring listed by its Yuchai part number. If you need to cross-reference with a later variant, check Yuchai YC4D 2005 Parts Catalog – OEM Factory Specs to see how the valve geometry changed.

Oil Pump, Filter, and Cooler: 3 Assemblies on Pages 25-29

Sections 12 through 14 cover the oil pump (B30-1011000), oil filter (G0100-1012000), and oil cooler (530-1013000C). Page 25 for the pump, page 27 for the filter, page 29 for the cooler. These sections include the bypass valve part numbers and the seal kits. If you’re retrofitting a cooler onto a base engine, the parts list here tells you exactly which lines and brackets you need. Parts Catalogue YC6M220G (M3020) Diesel Engine uses a similar oil cooler layout, but verify the thread pitch.

Fuel System: Injection Pump, Injector, and Turbocharger

Sections 18 (B30-1111000) and 19 (G0100-1112000) give you the fuel injection pump and injector assemblies. Section 20 (G0100-1118000) covers the turbocharger. These are high-precision, high-cost parts. Order the wrong injector and you’ll have a misfire that takes hours to diagnose. The catalog lists the delivery valve, plunger, and nozzle part numbers. For background on how these systems work, read the Automotive Industry Overview on modern diesel injection.

Why a Factory Parts Catalog Beats Aftermarket Cross-Reference

I’ve seen mechanics pull a part number from a third-party website, install it, and wonder why the engine knocks. The answer is always the same: the aftermarket site swapped a digit or used a generic supersession. This 79-page catalog is a direct reproduction of Yuchai’s own 2002 document. It’s printed from the original PDF — not scanned, not OCR-retyped. Every page is clear. Every part number is as Yuchai wrote it. Internal Combustion Engine fundamentals don’t change, but part numbers do.

Audience Fit: Who Needs This on the Bench

DIY guys swapping a head gasket on a YC4112ZQ in a generator set. Fleet mechanics maintaining G0800 engines in irrigation pumps. Shop owners stocking shelves with the right bearings. If you touch these engines, you need this catalog open on the tablet next to the torque wrench. It’s not a service manual — it’s the parts bible.

Does this parts catalog include torque specifications or repair procedures?

No. This is strictly a parts catalog. It lists assembly part numbers, component breakdowns, and quantities. For torque specs you need the factory service manual for the YC4112ZQ.

How do I identify which of the four variants (G0100, G0200, G0400, G0800) my engine is?

Look at the engine data plate on the rocker cover or the block casting. It will have the model designation stamped. The catalog groups parts by variant in the “Remark” column — items marked with an asterisk are unique to ZLQ versions (G0200, G0400, G0800). If the data plate is missing, cross-reference the cylinder head part number against the exploded views in section 3. That will tell you which assembly you have. The preface on page 2 explains the prefix system.

The parts you need for a YC4112ZQ G0100 or a G0800 are not the same. Don’t learn that the hard way. Access the Factory Manual now and put the right part numbers on your bench.