YAMAHA YR5
Our buyer’s guide!
The 1970 model year saw the launch of an uncomplicated, piston-ported, two-stroke twin that would lay down a basic genetic code for a raft of machines that would run for decades.
Lithe, Lithe stylish and potent, potent t the YR5 was a defining moment in Yamaha’s generall and two-stroke history; finally all the firm’s research , racing and technical know-how were crystallised into one machine.
Yamaha had had 350 twinns prior to the YR5 and although they were potent thhey had something of an old-world, gentlemanly charm m about them. That they were rapid was never in doubbt; Yamaha had used them as the basis for the TR350 series race bikes. However, the YR1, YR2 and YR3 styling was variously archaic, staid and u ultra conservative. The range was also bulky and argguably overweight/over engineered. The all-new YR55 (there is no YR4) was a ground-up design that owed little if anything to the older machines and when it, and its 250cc YDS7 sibling, burst upon the scenee they pretty much knocked everything else sideeways.
Part of Yamaha’s self-styleed Europa range, the bikes ran a two-tone paint sccheme unlike anything else that had come out of Japan before. The 350 YR5 was marketed with a whhite-panelled tank offset by candy red, orange or purpple with oil tank, side-panel, headlamp, etc., alla in matching candy… Yamaha had finally developed their own unique signature look. Dealers and customersc alike fell for
both the looks and performance of the new twin and, in America in particular, demand often outstripped supply. The year 1971 saw minimal change to the bike, other than a swap out of the white themed tank for black, and standardisation of the candy colour with just orange being available. Concurrent to this, Yamaha also changed the silencers from seamed units to smooth ones – other than that the design remained constant.
The YR5 was the beginning of a sea change for two-stroke twins and subtly shifted the paradigm towards performance and away from ‘everyman’ machines. Few who bought into the YR5 concept wanted to go touring, something that would have been unequivocally practical on the outgoing YR3. The new machine was more focused on point-andsquirt riding, traffic light grand prix, quarter-mile times and canyon racing. Yes, you could still happily ride Land’s End to John O’groats on a YR5, but the bike had an edge to it that rewarded fast riding.
The YR5 was a total re-design of the firm’s 350 twin and owed nothing to the older models, other than its capacity and general orientation of components. New barrels and heads were squared off and painted satin black with finished edges with the engine cases following a similar theme. Inside was a set of ports that owed much to Yamaha’s racing knowledge, with a dramatically over-squared bore and stroke arrangement aimed at raising maximum rpm. The chassis was also brand new and again influenced by track and competition knowhow. Styling-wise, the bulbous and gawky panelling had been dropped for an altogether sleeker appearance and suspension units front and rear were exposed, not shrouded. The other, obvious change was to the location of the front brake operating mechanisms which, like most of the rest of the range, was now on the left.
Both the 350 YR5 and 250 YDS7 lasted, in Europe and America at least, until early 1973 before being replaced with the RD series, which borrowed extensively on the design. In Japan there was a one-year only JDM (Japanese Domestic Market) model that ran the YR’S engine, chassis and panelling with an RD disc brake tacked on the front. These were known as the DX-PRO and RX-PRO.
So why might you want a YR5 now? Stunning good looks has to be a significant reason, as little else of the period looks quite so good, especially so with the white paint scheme. The model is fun and engaging to ride, fast enough for most classic fans and, crucially, has a much better than average spares and parts back-up. Providing your intended purchase has decent panelling, chassis and the basic engine cases, barrels and heads, you’ll be able to get what you need to keep it out there on the Tarmac. Low enough for those of moderate stature, light enough if you’re of advancing years, yet still able to put a huge grin on any fan of the ‘humble’ stinkwheels. What more could you honestly ask for?