Yamaha RD400 Parts (and RD250 DX)

Yamaha RD400

To continue in success and popularity of the "race developed" RD350, Yamaha in summer 1975 introduced a direct successor - the RD 400 series. Early Yamaha RD250 also continued with slight modification into the new era with most parts similar and identical to the new 1976 Yamaha RD400.

The new RD400 model was immediately branded as best of the RD series Yamaha built. It’s popularity was magnified by 1 year warranty with unlimited mileage provided by the Japanese manufacturer.

Both Yamaha RD 250 & Yamaha RD 400 have air-cooled two stroke twin parallel engines and autolube oil injection. In comparison to the RD350, the new RDs received: upgrade to the intake system, new reed valves, single piston disc front and rear brakes and cast wheels (wire spoke on 1976 Yamaha RD250). Yamaha RD 400 received a brand new 399cc rubber mounted engine that was free of vibrations. Both models had lots of chrome parts, lots of power and were made to last!

Yamaha RD400 Improvements over time 

In 1978  CDI induction was introduced and foot pegs were placed above the exhaust pipes, which now had longer mufflers and thicker manifolds.

1979  the RD400 diversified to meet stricter emission legislation throughout North America. To commemorate Daytona racing stars Kenny Roberts and Mike Baldwin, the new model was named Daytona Special. The main differences between US and Canadian version was ignition system and modifications to carbs and exhaust system.

Nowadays both models are in a restoration boom, with motorcycle enthusiasts revamping their rusty barn finds into stunning RD400 café racers and custom motorcycles. To find an original RD400 is an equivalent of finding a treasure.

RD400 Café Parts & RD250 Spares

Most of the original Yamaha RD250 parts and Yamaha RD400 parts are already discontinued. To fill in the gap and help keep these legendary motorbikes on the road, we decided to offer a whole range of quality reproductions.

We now have almost two hundred Yamaha RD 250 & spares for Yamaha RD400 now in stock and keep adding more.

If you can’t find the part you are looking for, please email us as we will do our best to source it out.

For further information about 79 RD400 Daytona Special models and their history visit The Morocyclist Online.

There is also lots of help available from fellow motorcycle enthusiasts on the Aircooled RD Forum

We also have a dedicated section to Yamaha RD250 LC parts.

Technical Specifications of Yamaha RD400

Model: Yamaha RD400

Year: 1976-80

Motorcycle Type: Standard Bike

Dry weight: 165 kg

Fuel tank size: 16.5 Litres

Engine, Intake & Transmission

Engine displacement: 398 cc 

Engine: 2-stroke, parallel twin

Top speed:  106.8 mph (171.9 km/h)

Fuel system: Mikuni Carburetors

Ignition: Points (CDI from 1978)

Lubrication system: Yamaha autolube

Cooling system: Aircooled

Gearbox: 6-speed

Transmission: Chain drive

Starting: Kickstarter

Chassis, suspension, brakes and wheels

Frame type: Steel tube

Ground clearance: 150 mm 

Front suspension: Telescopic forks

Rear suspension: Rear swingarm with twin rear shock absorbers

Front brakes: Disc brake

Rear brakes: Disc brake

If you require parts diagram or Yamaha RD400 parts list for any above, please contact us.