WR is merely the model name for the more enduro setup product line 4 stroke that Yamaha has ... might have a bit wider ratio transmission, a bit more toned down engine with a heavier flywheel weight with an extra gear or two in the transmission...
just a product line name like cobalt, malibu, impala in the chevy product line ...
similar to the XR or CRF-X in honda, DRZ in Suzuki, KLX in Kawasaki, etc...
It's a dual sport Yamaha. -Good Bike. But-Who knows what the WR stands for. I have a DRZ400 Suzuki dual sport, which is similar, and I don't know if the DRZ stands for anything, really. DR is Suzuki's line WR is Yamaha's.