Description

Yamaha WR426FP, WR426F, WR400F Parts Catalog

If you’re the kind of person who orders a piston ring set and gets the one for the wrong year, this is for you. I’ve been an ASE Master Technician for 28 years, running a 6-bay shop in San Antonio. I’ve seen more stripped threads and mismatched parts than I care to count. The problem is always the same: skipping the factory documentation. This Yamaha WR426FP, WR426F, WR400F Parts Catalog is 70 pages of OEM part numbers and exploded diagrams straight from Yamaha. No aftermarket guesswork. No reprints.

Engine Section: Cylinder, Crankshaft, and Valve Components

The Engine section covers Cylinder, Crankshaft/Piston, Valve, Camshaft/Chain, Water Pump, Radiator/Hose, Oil Pump, Oil Cleaner, Intake, Carburetor, Exhaust, Crankcase, and Crankcase Cover 1. If you need a specific part number for the camshaft chain tensioner or the cylinder head gasket, this is where you find it. Each diagram shows the exact assembly order and quantity. Page 5 of the manual shows the model label information so you can cross-reference your bike’s production code to the correct parts list.

Fuel System: Intake, Carburetor, and Exhaust

The Fuel section groups the Intake, Carburetor, and Exhaust components together. The parts catalog lists the pilot jet, main nozzle, and needle jet with factory part numbers. If you’re rebuilding the carb, you can verify the exact parts for your WR400F or WR426F. The fuel tank section is under Chassis, so don’t forget to check there for the tank graphics and cap parts.

Transmission and Clutch: Internal Parts Breakdown

The Transmission section includes the main shafts, gears, shift cam, shift fork, and shift shaft. The Clutch section covers the clutch assembly, plates, and springs. You’ll also find the Starter and Crankcase Cover 1 here. Having the factory parts list means you can order the correct number of snap rings or washers per assembly. That saves a return trip to the dealer.

Suspension and Chassis: Front Fork, Rear Arm, and More

The Chassis section covers the Frame, Fender, Side Cover, Rear Arm, Rear Suspension, Steering, Front Fork, Fuel Tank, Seat, Wheels, Brakes, and more. The Front Fork and Rear Suspension diagrams show the individual components like seals, bushings, and damping rods. The Rear Arm includes the swingarm and related hardware. If you’re rebuilding the suspension, this catalog ensures you get the right bearing and seal part numbers.

Does This Catalog Cover the Electrical System?

Yes. The Electrical sections include Generator, Meter, Headlight, Taillight, Handle Switch, Lever, and Electrical 1. There’s also an Alternate (Chassis) section. The parts catalog gives you the factory part numbers for bulbs, switches, and stators. Don’t trust a generic fiche for your WR426FP electricals.

Source Authenticity: Factory Yamaha, Not Aftermarket Reprints

This parts catalog is a direct scan of the original Yamaha publication. The OCR excerpt on page 1 shows the official YAMAHA logo and model list: WR426FP (5NG5) U.S.A., WR426F (5NG6) EUROPE, etc. There’s a foreword explaining how to order parts using the part numbers and abbreviations like ‘UR’ (Use specified parts number). No aftermarket catalog has this level of detail. I’ve seen third-party parts catalogs that combine multiple models into one generic diagram— that’ll get you the wrong part every time. Stick with this.

The importance of OEM parts is discussed in the Automotive Industry Overview and engine fundamentals in Internal Combustion Engine.

If you also work on sport bikes, the Yamaha YZF-R1 2002 Parts Catalog – OEM Factory Part Numbers might be useful. For earlier models, Yamaha GTS1000AE 1993 Parts Catalog – Factory Microfiche PDF and Yamaha V125 Parts Catalog – OEM Factory Part Numbers & Diagrams are available.

Does this catalog include torque specifications?

No. This is a parts catalog, not a service manual. Torque specs are in the service manual.

I have a WR400F from Europe. Will the part numbers match my bike?

Yes, the catalog includes the WR400F (5GSA) for Europe and Oceania. The model label on your bike will show the production code. Cross-reference that with the list on page 5 of the catalog. The foreword explains how to use the model code and production code number to identify the correct parts. Yamaha also issues Parts News for updates, so check for those. The exploded diagrams are model-specific, so the part numbers are accurate for your bike as long as you verify the production code. The catalog uses abbreviations like ‘UR’ for specified part numbers and includes quantity per assembly. If your bike has modifications, you may need to check the alternate parts list in the Alternate (Chassis) section.

That’s 70 pages of part numbers. You need this if you want the right part the first time. Don’t trust aftermarket parts catalogs. Get the real thing. Access the Factory Manual now.