Yamaha XS650
Yamaha’s 650cc XS models were built for the long haul, with one of the finest parallel twin engines of all time
Considering it was their first attempt at building a four-stroke motorcycle, Yamaha did a pretty impressive job with the 650cc XS series. It might have lacked some of the sophistication and aura of Honda’s four-cylinder CB750 which was launched in the same year, but the massively over-engineered XS1 engine could still show Honda a thing or two.
The 653cc XS1 first appeared at the Tokyo Motor Show in October 1969. It combined the expertise the company had gained with their impressive range of two-stroke bikes, with the cutting-edge overhead-cam technology their automotive division was starting to display. The ohc engine’s top end featured technology Yamaha had developed for the engine of Toyota’s 2000GT sports car, while the massive built-up four-main-bearing crank (with three roller and one ball race) was pure two-stroke practice.
And, while, at first glance, the bike may have displayed some styling similarities to the British twins of the day, the engineering and build quality represented a big advance.
The engine featured horizontallysplit crankcases with cast iron inserts for the main bearings, for a start. Then there was straight-cut gear primary drive, that overhead camshaft running on ball races (the CB750’S cam in ran direct in the alloy head) and a manual camchain adjuster that actually worked as intended. The end result was one of the most robust and durable Japanese engines ever built.
Development of Yamaha’s first four-stroke machine remained a fairly conservative process over the 14 or so years the 650 XS series remained in production. Broadly speaking, there are three basic incarnations (if you ignore the fairly unpleasant, though surprisingly popular at the time, ‘custom’ style S models). The first XS1 featured a twin-leading-shoe front brake, was kickstart-only and had no indicators. It was aimed at the US market and wasn’t available in the UK. An XS1-B version, with altered crank balance factor, appeared later the same year, while the 1971 XS1-F was the first model to sell in any appreciable numbers in Europe.
The next stage in the bike’s development was the 1972 XS2, with a single front disc brake, electric start and indicators. It was the first of the big XS models to be available in the UK, where it could take on its
British rivals head to head.
But the third stage of development was probably the finest flowering of the XS theme. Enlisting Percy Tait to iron out some of the slightly flighty handling characteristics of the XS2 and fitting a brace of disc brakes up front (for the UK at least), produced the XS650B (TX650-A in America). Handling was improved (at the expense of some added weight), braking was better and the bulletproof engine was as good as ever. Only the more restrained colour schemes were a backward step.
After that, development was minimal, with new forks and front brake calipers for 1977 and electronic ignition and smaller 34mm carbs for the final year of the ‘roadster’ style XS650-G in 1980.
But, if the XS650 dropped out of favour in the UK under a tide of four-cylinder missiles as the ’80s got underway, it remained something of a cult classic on mainland Europe. And that’s meant XS owners today enjoy superb parts back up from a few companies in Europe and America. That, plus excellent
reliability, ton-up performance and prices that haven’t (yet) gone through the roof, makes the XS650 a thoroughly practical, affordable and fun classic to own today.
THE RIDE
Any XS650 provides the punchy power of a Brit twin, with a little more sophistication thrown in. They’re pretty much on par with Triumph and BSA’S unit construction 650s on power – around 50bhp. And, even though they weigh more, the straight-line performance, aided by the sweetshifting five-speed gearbox, is comparable. The handling isn’t quite as precise as the best of the Brits, but on the road it doesn’t compromise your riding pleasure. The vibration between 4000 and 6000rpm might do, though – which is why Yamaha went for more rubber insulation for the ’bars and engine on 1974-on models. In truth, though, it’s no worse than many other parallel twins and it’s probably something most owners can learn to live with.
Firing up even an early kickstart XS1 is easy enough and the Xs2-on models all have electric start anyway. Braking is better on bikes with the twin-disc set-up and the handling is better on the Taitdeveloped XS650B and onward versions. That said, the handling of the XS1 and XS2 is nowhere near as bad as the myths suggest. Stick some decent modern tyres and a good pair of shocks on and you’ll probably be quite happy, unless you want to ride flat-out everywhere.
But ride as most of us do on our classics and an XS is a delight. Yes, it may be heavier than a Triumph; no, it’s not as fast as a CB750 or Z1. But it’s fast enough to have fun – and even frighten yourself a little bit, if that’s what you want – and it feels slim, sling-able and lively.
It’ll also keep on doing so for mile after mile, year after year, with just routine maintenance. Not all classics will do that. If you fancy one that’s easy to live with and won’t break the bank, an XS650 is well worth a look.