My opinion, As long as it starts easy enough It doesn't matter if ya gotta choke it a bit. You say it runs good after it's started, leave it alone. My bike starts a little hard for the first time of the day, but after that it starts very easy, (till the next morning again.) I pump the 'Tickle button" untill it overflows for the first start of the day. It just starts easier with fresh fuel down the throat. You may get it to start REAL EASY, then perhaps it don't run as well. I've always said, If it ain't broke, Don't fix it. Sometimes when ya keep trying to fix something that ain't broke, It will be.
But then if ya gotta choke heck out of it EVERY TIME, even after warm up, then you might try bringing your needle up a notch. If that don't do it then you could try a little bigger jet. Sounds like you might be running just a little lean. Good enought to run when it's warm but making it hard to start. also, You didn't say if you were using the primer ("tickle") button or not.
fatdaddy.
Forgot to ask, Whats yer plug look like?