Painting Exhaust, Where to Mask?

[Pelikan]

I'm getting the exhaust blasted and will be painting soon.  I'm putting a Yosh TRS on there, so it'll be hacked to about the length depicted in the below picture.  I'm wondering what, if anything, should be masked.  The holes leading into the engine?  The inch after that kerneled thing at the top of each header?

Also, it's been recommended to clean with acetone before painting.  Do you just rub the thing down and let it dry?

[Big Rich]

If you're painting the exhaust while it's off the bike, then nothing needs masked off.

You're better off not wiping the acetone. A rag will leave small fibers and alcohol dries very quickly.

[The Buddha]

No masking needed. May be the chrome on the can ... even that you can stop before you get on it. Nothign gonna happen if you spray in the ports.
BTW as soon as you paint it and it dries, I'd fit it on the bike and start the bike and idle it for 20 mins till all the paint cures. Any spot you have missed - paint it again or scrapes etc too ... spray right on the bike, just wait till it cools a little.
Cool.
Buddha.