YAMAHA XS1, XS2 & TX650

FOR A COMPANY THAT MADE ITS REPUTATION with two-strokes, Yamaha has always had something of a thing for large capacity four-stroke twins. Think the Ducati aping TRX850, its 850/900 TDM cousin, or how about the massive trail iron, the Super Ténéné XT1200? Recently the firm has enjoyed amazing success with the DOHC 700cc MT-07, yet this is a love affair which goes back to the late 1960s.

XSl GENESIS

Yamaha's seminal 650 twins were created in response to a 1965 USA move towards cleaner air. The nascent bill was due to be enacted in 1968 and so,just as Yamaha's smoking twins were becoming popular stateside, it looked like they might well be doomed. Therefore Project 049, headed by Daisuke Tanaka, commenced in August 1967 to develop a market-competitive four-stroke twin. The bike's origins were absolutely atypical and didn't follow what many might view as a conventional or industry standard route to designing an