I have a 99 Fatboy with V&H 2 into 1 exhaust. It had a rejetted, stock carb on it. I replaced it with a Mikuni 42. That made a significant difference in throttle response and virtually eliminated the caughing that was still occasionally present even after rejetting the stock carb. They are a little pricey but they are very easy to install and can be adjsusted easily as well. PLus you'll already be prepared when you add the stage II kit down the road.

This is the third one I've had and I've been very happy with the performance. I would have no quams about buying another one. I got the last one on sale from DP for around $250.
All three times I was able to bolt it on, make a few very minor adjustments and be on the road in an hour or two. I'm not sure about the 01 but on the 99 your supposed to re-route the throttle cables a little which requires removing the tank.
Do a little homework and be sure you have the bracket and breather that will allow you to have the air cleaner/cover combination you want.
Good Luck and Safe Riding
