By guest writer Tom Stewart. Hard core café racers are generally built for show and go—there aren’t many built for daily commuting and long-distance touring. But this air-cooled Yamaha RD350B, purchased new in 1975 by the late British racer Howard Lees, didn’t stay in standard trim for long. As an engineering under-graduate teenager, Lees quickly tore it apart in a quest for the perfect yet affordable road-going motorcycle.
History doesn’t relate why this RD’s frame was replaced by an earlier, very similar item from a 250 DS7. (A major shunt could be one reason.) But the Koni rear suspension and two-inch longer Dresda box-section swing arm with tapered roller bearings are obvious improvements from standard. Lees added wheels, forks, brakes and engine covers from an RD400 a year or two later, along with a pattern TZ250/350 race fairing—modified to accept twin endurance-style Cibié headlamps. Then came a Lees-designed and fabricated tank, seat, front mudguard, oil/battery box and rear-sets.
To keep pace with the superbikes of the day, and inspired by US tuning house Denco, Lees tuned the RD350B motor by modifying the crankcases, ports, pistons and heads. He substituted the standard 28mm Mikunis for 34mm Amal Mk IIs, delivering their mixture through big, six-petal DT250 reed valves. A Lucas CDI ignition with a pair of large coils provided sparks; a beefed-up RD clutch, Lees-designed expansion pipes (originally minus the alloy end cans) and substantially taller final gearing completed the mechanical spec. Horsepower isn’t known, but around 50bhp seems reasonable. What is known is that this RD350B could cruise all day at 100 mph, and—unburdened by luggage—hit a max of 125 mph (200 kph). Impressively, a more moderate 85 mph cruising speed would yield around 55mpg.
As was always intended, the RD350B transported south Londoner Lees far and wide, from the Isle of Man TT to the Dutch TT at Assen, and from Circuit Paul Ricard to the Italian Riviera to the Munich beer festival—the latter trip once involving a detour around Switzerland via Austria, as Swiss border guards declared the the unsilenced pipes to be too noisy for their country.
The bike was the topic of a feature entitled Renegade Racer in the July 1979 issue of the UK’s Bike magazine. Inevitably it occasionally felt the heat of club-level competition at Brands Hatch and elsewhere during the very early 1980s. Unfortunately a seizure and crash in the south of France, coupled with Lees’ burgeoning racing ambitions—and his untimely death aged 34 in late ’92—meant that the broken RD languished in various sheds. In the mid-noughties it was eventually repaired and put back on the road; more recently, new owner Ian Martin won the Post Classic 500cc air-cooled class on it at the CRMC Easter 2010 meeting at South Wales’ Pembrey circuit. Not too shabby a result for a home-built, unrestored, 35 year-old two-stroke ‘tourer’. [Check the Howard Lees website for more details of the team's race bikes.]