About the Yamaha DT400
Match DT400 fork-seal dimensions, clutch years and the original fuel-tap arrangement.
Yamaha introduced the DT400 in its 1975 product range. For a motorcycle restored with parts from different years, identify the fork, engine and fuel tank before building the order. The frame’s year remains useful, but it cannot identify a replacement assembly on its own.
Measure the original fork seal before ordering
The fork seals provide a clear size check: the 1975–1978 listing specifies 34 × 46 × 10.5 mm, while 1979 specifies 36 × 48 × 10.5 mm. The clutch plate covers 1977–1979 and the fuel tap 1975–1976. Keep those narrower applications attached to the relevant repair.
Know your model before choosing partsYamaha DT400 repair checkpoints
Use the complete model, year and fitted assembly. Each product has its own application and package contents.
1975–1978 fork application
The earlier seal listing is 34 × 46 × 10.5 mm. Compare the original seal and fitted fork.
1979 fork application
The later listing is 36 × 48 × 10.5 mm. Do not choose the earlier seal simply because both products mention DT400.
Clutch and fuel service
The featured friction plate lists 1977–1979; the fuel tap lists 1975–1976. Those separate applications do not extend each other.
Identify your model before orderingYamaha DT400 identification checklist
Use the identification on your machine and the component being repaired.
- Record the motorcycle’s model year and engine identity.
- Measure the old fork seal and check fork markings if the front end has been changed.
- For fuel-tap replacement, compare tank mounting, outlet orientation and the installed tap.
Contact PartsNMore with the complete model, year and clear photos of the identification and original part.