Have'nt got a 4S but my bike seems to like what seems to work for most Dukes. It needs just a tiny tweak of the fast idle when cold (none when hot) but I never touch the throttle when starting.
Found out that if you do it just spits and pops at you. Leave the throttle alone until it's warmed up (that'll be good for getting oil flow to your rockers as well)
Jools
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