Carb change for 1200 sportster (sport model)

I'm wondering my stock carb on my 1200 cc sportster is terrible when cold, spits, belches, I've changed the low speed jet to a 45, the high speed is a 175, Is it worth it going to a Mikuni to avoid all this?. Or should I continue to put more time and effort into the stock carb.

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Orignal From: Carb change for 1200 sportster (sport model)