Building on the success of its popular 200, 250, and 350 RD series machines, Yamaha introduced the RD400 in 1976, continuing to produce variants of the model until 1980. The Japanese air-cooled two-stroke wasn’t just a favorite on the street, but the RD400 was a go-to choice for many when searching for a race platform. The 398cc Yamaha was seriously fast for its time, capable of a standing quarter-mile in 14 seconds flat. The parallel-twin 400’s predecessors were highly developed machines, so when it came time to bump the 350 up to 400, the bike already had a major leg up.
In its stock form, the 1978 model was powered by a 398cc two stroke that reportedly made 44hp at 7,000rpm and 30.3ft-lbs of torque at 6,500rpm, making the sporty six-speed Yamaha good for around 107mph. The air-cooled powerplant on the RD400 is undeniably responsible for much of its success, however the tubular twin-cradle frame wrapped around said powerplant played a major role in the bike’s performance capabilities. As did its relatively advanced telescopic fork and dual rear-suspension. The 400 also weighed in at 364lbs wet, though other sources say that figure is actually closer to 350lbs.
Various changes and updates were made to the RD400 in its half-decade production run. In 1977 – the second year of the RD400’s production – Yamaha added a new seat cowling and more importantly equipped the bike with cast rims (an add-on in ’76 that became a standard feature in ’77) which at the time was a first for a production bike. Then in ’78 the RD got a CDI ignition unit, in addition to thinner cast wheels, a new rear-set position, and some minor mechanic tweaks to the engine.
As great of a bike as the biggest RD was, it wasn’t without shortcomings, some of which were a result of it being so strong in other areas such as its impressive speed and acceleration making its less-than-awesome brakes markedly more noticeable. This same white-knuckle-inducing acceleration also resulted in a lot of stress being put on the engine which in turn caused problems. Small components would often need replacing, the crank seals frequently broke and sixth-gear had some issues with wear. Fortunately some of these problems can be remedied with the right modifications.
This particular RD400 example appears to be in excellent condition cosmetically, and pristine hardly begins to describe the engine. The seller describes the example as “The best RD400 Race bike”, and claims $10K was spent on the engine alone. Other upgrades include Brembo calipers, – which solve the stock brake problems – a fork tuned by RaceTech, cylinder-head temperature sensor, Works Performance Racing aluminum shocks, and a Spec2 exhaust. This example is currently being sold at The Garage Company in Los Angeles and though they sometimes have steep prices, Yoshi and the rest of the gang are reliable and professional so I’m often inclined to believe them when they describe the condition of a bike.
A big part of the RD400’s appeal when it was first unveiled is how straight-up badass it looked. Its trademark coffin-shaped tank and sweeping bodywork gave it an aggressive look that attracted – and continues to attract – legions of riders. The sound of an RD400 going flat-out is definitely another selling-point of the bike’s. The thing screams and is simply a beast, encapsulating everything people love about two-stroke racers. My hands-down favorite cafe-racer of all time was an RD400-powered build in a TZ250 frame that Roland Sands built, called “The Two-Stroke Attack”, and there’s little question as to why the builder, motorcycle icon, and ’98 AMA 250GP National Champion opted to use the legendary RD400 to build a racer around.
This example is said to be safety-wired and race-ready, It meets all AHRMA regulations and is 100% ready to go. The ad fails to specify this example’s production-year, but my guess is that it’s one of the later models. You can find this upgraded Yamaha RD400 racer for sale here on Craigslist in Los Angeles, California at the Garage Company with a price of $6,500.