I most always run my 650 in low due to the terrain I ride. Lately when I want to shift out of low it doesn't want to shift freely and I have to give a little throttle to make it roll a little and then it will shift out. Once out of low it shifts easily to other shift positions. Could this be a linkage problem or signs of transmission trouble?

 

From my experince your bolt on the side of the engine for your linkage shifter is loose, also I find a small craw coasting forward helps a lot.