You don't need to idle them, idling you won't get temps up to what is considered ideal to expand the metals and tolerances. After the second idle tank, run it around slowly (half throttle ok, no more) for the third tank, let the engine use it's torque just a little bit, and try to get temps up to about 200, then cool it, lean it a bit and repeat aiming for over 200. Do a couple of tanks this way, maybe 3 and then start tuning. Just remember, cool it completely between tanks WITH THE PISTON AT BOTTOM DEAD CENTER!