IT’S THE NOISE AND acceleration above 6,000 revolutions per minute that are still so addictive; the sudden burst of activity every time the throttle is wound back in anger and the 347-cc two-stroke motor comes alive. You might think the thrill would have worn off after all these years, especially now that so many modern bikes produce far more performance than this early-1980s twin. But if the little Yamaha can no longer deliver the giant-killing speed on which its mighty reputation is based, it still puts a broad smile on its rider’s face with every ride.
So much so that if you were to make a list of the most popular motorcycles of the last century, the RD350LC should surely be included, and somewhere near the top, too. It might have produced less than 50 PS and had a top speed of not much more than 160 km/h, but for many riders Yamaha’s raw, racy LC was the high-performance bike of the 1980s — or any other decade. Certainly, few machines can have brought so much fast and furious enjoyment to so many as the liquid-cooled two-stroke twin that Yamaha unleashed in 1981.
In many ways, the LC had the lot: speed, excitement and handling — plus reasonable practicality, reliability, and economy. Although it had an appetite for fuel and two-stroke oil, it was relatively cheap to buy and to run. And it looked great, too, with a restrained style that contrasted with its outrageous personality. No wonder it was such a success.
The RD350LC was a descendant of the string of outstanding air-cooled two-strokes with which Yamaha had established an unmatched reputation for middleweight performance. The line had begun with the YR1 model back in 1967. And throughout the 1970s, models such as the 350-cc YR5, RD350 and RD400 had kept the tuning-fork logo to the fore. The “RD” initials stood for Race Developed and were well earned because most of the Yamaha twin’s gains in performance and reliability were due to the firm’s efforts on the track.
Stars such as Phil Read and Jarno Saarinen had won on Yamaha’s air-cooled twins in the '60s and '70s before Yamaha introduced the liquid-cooled TZ250 and 350 with equally spectacular results. When the RD350LC roadster was launched in late 1980 — the “LC” standing for Liquid Cooled — South Africa’s Jon Ekerold had just won the 350-cc world championship on a Bimota-framed TZ, while Kenny Roberts had completed his hat-trick of titles in the 500-cc class.
The new LC roadster engine, whose 347 cc capacity came from dimensions of 64 x 54 mm, produced its 47 PS maximum at 8,500 rpm. It differed from the racing TZ motor in numerous ways, including its use of two separate cylinders, reed valve induction, and rubber mounts to combat vibration. Its liquid cooling allowed a more constant engine temperature and closer tolerances, as well as reducing noise. Not that this was enough to get the two-stroke through ever-tightening emission regulations in the States, where it was not officially imported.
Chassis layout was also influenced by Yamaha’s racers, as the air-cooled RD400’s twin-shock design was replaced by a monoshock system, featuring a cantilever swingarm operating a shock unit located diagonally under the seat. The 18-inch cast wheels had stylishly curved spokes but in other respects the chassis was conventional, with a twin-downtube steel frame, slightly raised handlebars, and a twin-disc front brake, with a drum rear. (The similar RD250LC, introduced at the same time, was visually near-identical apart from its single front disc.)
Perhaps surprisingly, the initial reaction was not universally favourable, with some testers wondering whether the LC was too peaky and aggressive to appeal to more than a limited section of the market. Well, maybe it didn’t appeal to everyone — but for all those riders looking for high performance on a low budget, no other bike even came close. With a top speed of 175 km/h, wheelie-popping acceleration and racetrack credibility, this was the stuff every speed-crazed teenager’s dreams were made of.
The LC needed little help to become a huge hit for Yamaha, but got some assistance anyway in the form of a hugely successful one-make racing format. This began in the UK as the RD350 Pro-Am Series, which was contested by a mixture of professional and amateur riders (hence the name), including future 500-cc works GP star Niall Mackenzie. They rode identical LCs, prepared by Yamaha and allocated after keys were drawn out of a hat. The result was close, aggressive, and spectacular racing, which soon led to an international series that included riders from many European countries, besides Australia.
These days the RD350LC is fondly remembered by many riders who used to own one, including Mackenzie, who has restored one to immaculate standard condition (and has ridden in the recent “Pro-Am” revival races at tracks, including Silverstone and Knockhill). The bike tested here is not in quite such good condition, having some peeling paintwork on the engine, plus a few other minor flaws. But it is still a neat-looking machine and great fun to ride.
The entertainment begins the moment you kick the engine into life (there’s no electric starter) and the two-stroke powerplant comes to life with a burbling, rather harsh sound through those twin pipes which also belch out a fair bit of smoke and fumes. Along with good, clear instruments, the Yam has excellent controls and a light clutch. Some play in this bike’s gear linkage means the change is less smooth than it should be, but the six-speed 'box still works well, and for a rev-happy two-stroke the Yamaha is very easy to ride in town, where its relatively upright riding position also helps make it comfortable.
It’s out on the open road, though, that the 350LC comes alive. One moment the bike is dawdling along behind a line of cars; the next, there’s a gap in the oncoming traffic, I’m cogging down two gears, winding back the throttle, and holding on tight as the Yamaha streaks towards the horizon with enough force and noise to send a tingle down my spine.
Somehow the wind-blown riding position and the high-pitched shriek of the exhaust combine to make the bike feel as though it’s travelling faster than it really is. In reality, the realistic maximum cruising speed is not much more than 140 km/h, so there’s no way the LC is particularly fast by modern standards. But at least, with speed cameras to worry about these days, it can be thrashed on main roads without too much danger to your licence.
The Yamaha also provides plenty of entertainment in corners, where its light weight (140 kg) is the main reason for its flickable handling. Nobody who ever saw the outrageous manoeuvres that took place during a typical RD350LC Cup race will doubt that the bike’s frame is stiff enough, and its basic geometry and chassis layout good enough to allow hard and fast riding. This bike’s suspension feels a little soft and bouncy at times, but still encourages me to throw the bike into turns with plenty of enthusiasm.
Among this LC’s very few non-standard parts are the braided front brake lines, which help the twin discs’ old-fashioned single-piston calipers deliver a respectable amount of stopping power. A narrow pair of Pirelli Mandrake tyres doesn’t give the grip of wider radials, but they’re well up to making the most of the slim twin’s ground clearance — of which there is plenty, as befits a bike that was built for performance above all else.
Reliability was another of the LC’s many attributes, both on road and track, although it wasn’t infallible. Engine studs sometimes broke and exhausts cracked due to engine vibration before the design was modified. Yamaha updated the carbs to prevent misfiring, revised the rich-running oil pump and beefed up the exhaust mounts with tie-rods under the engine. They also introduced a new black/red “Mars Bar” colour scheme along with an optional bikini fairing and belly-pan and, in some markets, a full fairing.
The original LC’s reign was short, because for 1984 it was replaced by an all-new model, characterized by the new exhaust, whose flap moved at a certain revs to optimise volume for both high- and low-speed running. The YPVS (or Yamaha Power Valve System) gave slightly stronger mid-range delivery with no loss of top end and led to the bikini-faired Yam, officially the RD350LC YPVS, being known as the “Power Valve”. Other mods, including a bikini fairing, air-assisted forks, rising-rate shock, and tubeless tyres, helped make it another hit.
That mid-1980s period of the Power Valve’s rule was probably the high point of the RD350LC’s existence, but the model was not finished yet. The fully faired 350LC F2 and naked 350L N models were also fairly popular, partly because switching production to South America helped keep prices low. The fully faired LC initially had a rectangular headlight, then went to twin round headlights in the early '90s, by now called the RD350R.
With its performance little changed, the Yamaha was inevitably less competitive; most young riders dreamt about the more glamorous and expensive FZR400RR four instead. But by the time the two-stroke was phased out in the mid-'90s, it had lasted in its various forms for well over a decade and sold in a huge number all over the world. More than two decades after that, it’s quite simply one of the best-loved bikes of all time.
Configuration: Water-cooled, two-stroke, parallel twin
Displacement: 247 cc
Bore x Stroke: 64 x 54 mm
Compression ratio: 6.2:1
Fuelling: Twin 26-mm Mikunis
Maximum Power: 47 PS at 7,000 rpm
Maximum Torque: NA
Electrics: 12V battery; 60/55W headlamp
Type: Tubular steel cradle
Front suspension: Telescopic, no adjustment
Rear suspension: Monoshock, adjustable preload
Front brake: Twin 267-mm discs
Rear brake: 203-mm drum
Front Tyres: 3.00-18 Pirelli Mandrake
Rear Tyres: 3.50-18 Pirelli Mandrake
Wheelbase: 1,550 mm
Seat height: 787 mm
Tank capacity: 16 litres
Weight: 140 kg (wet) ■