The rubber on the carb manifold on my IT400F is cracking on the outside, hasn't gone all the way through yet. Since this is a one year engine it is really hard to find a replacement. Any ideas on what to apply to the cracked areas to ensure they don't open up any more and go deeper into the rubber?

Just because, my rubber boots leak once in a while, I lightly scuff and use rubber cement… I haven’t had to repair, a repair… only the new ones that show up..
Sneezles61

Probable replacement here: www.dcvmx.com/xcart/product.php?productid=182990&cat=&page=2

I noticed some light cracking on my DT400C manifold so I just used some black RTV and smeared it all over, smoothing it out as best I can so it's not really noticeable.

I used cyanoacrylate - commonly known as crazy glue - on a split in an intake manifold and it worked great