It is a development of the original XT series ('X' stands for 4 strokes, 'T' for TRAIL), a line of motorcycles inspired by those used on the Paris Dakar rally. The first XT was released in 1976. The XT660R is the standard Enduro model ('R' stands for racing).
A five-valve version of the 660 cc engine was used in a number of MZ (MuZ) motorcycles, including the MZ Skorpion, Baghira and Mastiff.
After 2015 this bike was not sold in some European countries and US.
Yamaha XT660 X 2008 facelift
Two other versions of this motorcycle are being produced alongside the XT660R – the XT660X, a more street-oriented supermoto version, and the XT660Z Ténéré, an adventure touring version,. All versions utilize the same engine and share some chassis components.