This was originally posted on APC forums on 11/11/2011
The honda requires some smarts in the transfer switch. The UTS has two relays that it uses to start/stop the honda. One will spin the starter, the other is to kill the engine. This means the UTS has to handle the starting logic (spin the starter, verify it started, repeat if it didnt etc). Other generators require just a single relay in the transfer switch. The relay closes to signal the generator to start and opens again to signal stop. With this setup, all the starting and retry logic is in the generator. Clearly, if the UTS can start the honda, it's just a couple of lines of software from being able to start a two-wire start generator. It has all the necessary hardware.
The instructions for the honda auto-start kit are but a google search away. It's pretty clear from the "included parts" list that the kit isnt really needed. It contains just two readily available parts costing less than $2/each. The most interesting thing about the kit turns out to be the instructions as they refer to menu options in the UTS that are not mentioned in the operators manual. But rather than describe the options completely they only mention how to set them to start the honda's listed in the introduction. I'm guessing, but have no way to confirm, that setting these options differently would allow control of a two-wire start generator.
It's starting to look like I'll have to get my hands on a UTS to find out.