I would just use the trim on the radio to set your idle, that's kinda what it's there for. As for tuning, the manufacturers usually set the lsn at the factory, and is generally a good place to start. Once you get the engine broken in it might need tweeking for best low speed performance. The way I do it is to set the hsn, then let it idle for a couple of seconds and see what happens. If it bogs down and produces a lot of smoke, I'll tighten the lsn by an eight of a turn. If is bogs down and doesn't blow a lot of smoke, I losten the lsn. It is important to note that everytime you adjust the lsn, the hsn will have to be retuned.