It depends...if it's going to die and then fires up again,and you think that it's not smooth then maybe the idle it's too low.

After you go to idle it should lower rpm from high idle, after at least 10s(some say more than 20s,others more than 1min,...) the longer it stays the leaner is your LSN.(correct me if i'm wrong but these are info from different sites).

And also try richening the HSN around 1/8th(H21 8 port needles are toooo "sensitive") of a turn,260-270 is kind of high.

What's the ambient temp there?
What fuel are you using?
What plug do you use?

Some more info will help a lot!