Any one knows is it possible to change fuel tank tap without some large disasemble of bike?

Just did it on a 2014 300 Evo. Required removal of the rear fender, air box, carb, carb intake manifold, and exhaust manifold. With those parts out of the way the fuel tap can be pulled out

The quickest and easiest way is to remove the carb, then unscrew the fuel tap from the tank. The tap has a long filter which goes inside the tank, pull the tap from the tank while gently bending the filter to clear the inlet manifold. Replacement is reverse of removal, but start with the fuel tap nut just started on the first thread on the tap. It has a left and right hand thread, so it pulls the tap on to the tank threads as you tighten it. This method can be done in around 10 minutes.

Thanks a lot. I will try that.