Part of the Yanmar Parts Manuals.
An OHV gasoline engine comes apart quickly on the stand, and the job stalls just as quickly when you cannot put a real Yanmar part number on the ring set or governor spring sitting in front of you. This parts catalog, Yanmar publication Y00B4451, covers the GA120 and GA120RDZB gasoline engine and exists to answer exactly that question.
Across its 20 pages the catalog works through the engine assembly by assembly: Cylinder Block, Cylinder Head & Bonnet, Air Cleaner & Muffler, Crankshaft, Piston & Camshaft, Carburetor, and the Governor & Control Device. Each section lists the factory part numbers for components down to seals, pins, springs, and hardware, so a worn rocker arm or a cracked float chamber body gets ordered correctly the first time.
The PDF is small (0.41 MB), in English, and bookmarked by section. Bought once, it stays with this engine for every rebuild after this one.
What's Inside This Parts Manual
| System | Pages | Key Topics |
|---|---|---|
| Cylinder Block | 1-3 | Cylinder Block Assy, Oil Seal, Gasket, Side Cover Assy, W/ Lub. Oil Gauge Cap, Lub. Oil Cap, Joint Filler |
| Cylinder Head & Bonnet | 4-5 | Breather, Breather Pipe, Cylinder Head Assy, Intake Valve, Exhaust Valve, Valve Spring, Spring Retainer, Rocker Arm |
| Label | 6-7 | Ohv Mark Label, Caution Label, Drain Label, Air Cleaner Label, Recoil Start Label |
| Air Cleaner & Muffler | 8-9 | Air Cleaner Assy, Air Cleaner Cap, Air Cleaner Element, Air Cleaner Body, Element Holder, Carburetor Gasket, Muffler Gasket, Muffler |
| Crankshaft, Piston & Camshaft | 10-11 | Camshaft Assy, Decomp Spring, Tappet, Push Rod, Crankshaft Assy, Crankshaft Gear, Idle Gear, Piston Assy |
| Carburetor | 12-13 | Carburetor Assy, Throttle Valve, Choke Valve, Pilot Jet, Spring, Needle Valve, Float Assy, Throttle Shaft |
| Governor & Control Device | 14-20 | Governor Spindle, Governor Lever Shaft, Governor Gear Assy, Governor Spring, Control Assy, Control Lever Assy, Control Base Assy, Base Assy |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Parallel Pin Size | 8x12 mm | p. 16 |
| O-Ring Size | P-18.0 | p. 2 |
| Stud Size | M8x18 | p. 4 |
| Key Size | 4x10 mm | p. 16 |
| Hose Diameter | D5/3 | p. 12 |
| Circlip Size | E-4 | p. 18 |
