I am fairly new to RCs as well but if I am not mistaken you will and should only see smoke when under throttle. I know my buggies don't smoke from the exhaust at idle but when I apply the throttle there is a nice trail of smoke.

As far as richening/leaning the needles....rich is counter-clockwise and lean is clockwise. Hope this helps and I am sure the other guys/well seasoned RCers will be by to help.