Not sure man, just lean it out till it goes well
I just found mine goes MUCH better on a hot plug. Needle settings will depend on your location etc, mine are different at home to when I drive 1.5hrs to the "local" track.
IMO Starting a cold engine and letting it idle is much more stressfull on the engine then pre-heating, starting then driving it around (keeping temps up)
When you sit there and idle tanks away the engine does not get up to operating temp, the sleeve etc does not expand to the normal operating size and you are breaking in a engine at a temperature its not going to be operating at = wasting life/compression on the engine.
I wrapped a cloth around the cooling head of my engine when driving it to get the temps up to 200f so it was run closer to normal operating temps. I also pre-heat my new engines before starting (untill they are broken in)
But thats just what I believe in, others have different methods
Ive tried the idle method, and I like to run'em now. I think my next engine will be pre-heat, start, run...