[fastpat]

I'd see if there was a model of this carb with changeable jets on any bike. If not, then you have the decision to, 1. leave it alone (drilling the jet won't work), 2. extracting the pressed in jet, tapping the bore, and installing an adapter for a removable jet, or 3. doing a carb swap.

I had a similar 750 model, and those carbs were crap when they were new, the bike was never really smooth in around town driving.

Take a look at Keihin flat slide carbs.