How do you know you got your jetting right ?

[Krisden]

I've just replaced my exp pipe because of a nasty crash crushing the old pipe
Now my bike seems faster and uses less fuel but the first part of the pipe have turned a gold color (heat ?)
I'm new to gas gas and im now questioning if my jetting was or is now right
how would i gauge that ? is there a right sound or ping ?
being new to gas gas i cant really tell if the power is right
any help would be nice six year off a 2t has made my a noob again