I did that years ago. Bought a spare set of carbs from a member here and had them set aside until last summer. They were not in good shape. Paid about $275 back in 2007. I rebuilt my ‘99 Valkyrie’s original carbs two years ago and decided to do the same thing to the spare set last year.
Last summer I rebuilt them with all new components, using the redeyetech big kit. I bought all new jets (oem, not the knock offs you find on eBay...beware of their quality), new floats and float valves, all new rubber insulators (intake connectors), tubing including drain lines, fuel lines and air tubing. I rebuilt the air cut valves and tested them to ensure they were functioning properly. All in about $700-$750. Plus at least 4 cans of carb cleaner, cans of compressed air, and a week of bench time to make sure everything was done as well as I could. All the air passages need to be scrupulously clean.
This is why I have two sets of used jets...I even bought the redeyetech o-ring kits to put on the used pilots just in case.
Next time my carbs need service I have a spare set to swap in without a week of downtime.
