Yamaha’s RD250B was one of those overlooked and somewhat marginalised motorcycles of the 1970s.
When the air-cooled RD250/350 duo were unveiled in 1972 for the forthcoming model year, Yamaha’s rivals probably didn’t even do much more than have a cursory peek. By the end of 1973 Suzuki and Kawasaki were certainly sitting up and taking notice – less so Honda who had their focus well and truly on cars at the time. The RD350 simply blitzed everything else out there regardless of capacity and the RD250 simply cleaned up on learner sales. Arguably, the 250 twin made the same impact on Japanese quarter-litre salesdisc front brake; and those all-important reed-valves. It was an instant best seller straight out the crate.
