Fast idle speed

Hi all, I'm new to this site and moto guzzi, allways had jap stuff but fancied a change! I've just bought a 1200 GRiSO and think its great, However!!! On cold start it idles slowly and very unevenly like fuel enrichment not working, But once its warmed up the idle speed then wont go below 1500/1600 rpm and fueling at low speed and very light throttle openings is a bit on/off. Also it has a bit of a whining noise from the alternator area, Not bad and don't know if that might be normal. I bought this from a guzzi dealer and had it delivered when I wasn't home and its a long ride to take it back, Any ideas on the fuelling would be good, Cheers all.

More details will help.

What year? If pre 2013 has it been rollerised? Is the paint still intact on the throttle stop screw on the LH throttlebody? How about the linkage rod? Have you touched anything yet?