"You don't "bore them out".
Easy Rider... In machine shop lingo....when you increase the size of a hole ( or port on a carb) we say it has been "bored" meaning to have increased the inside diameter or ID. I found this Kit for sale
http://cgi.ebay.com/ebaymotors/ws/eBayI ... K:MEWAX:IT
Installing a jet kit in your carb
Kit Includes
Main Jets
Needle Adjusters
Nylon Spacers
Drill Bits for
Slide Hole Modification
Idle Mixture Modification
Slide Spring Modification
Bike Specs
Carb Schematic
Is it worth the effort and the money?