Hi all!  First off, I'm a new 2005 Suzuki S40 rider (and a new rider in general) and I'm really glad that I found this forum.  The wealth of information that I've already learned just browsing around is amazing.

So, as I said, I just recently bought a completely stock 2005 S40 with 4,000 miles on it.  I've noticed that when I don't ride for 2-3 days, it dies shortly after I start it up if I'm not on the throttle for ~1 min.  In other words, it starts up but idles so low that the engine is killed unless I give it a little gas with the throttle (or choke) until it gets a bit warmer.

Is this typical?  Or is it indicative of some maintenance that needs to be done?

My 2009 does that on occasion.   I rarely ever have to use choke, but when it starts it idles really low and may die if I don't rev it occasionally during the first 30 seconds or so.

Air filter is a possibility...
It's under the side cover on the right side... Remove it, and hold it up to the sun or a bright light... if it appears translucent, and you can see some light passing through it,... it's okay...
If it appears solid grey/black,.. you need to replace it...

It's also possible that your speed is a little too slow... that's not good.  The oil pump needs about 1,000rpm to have decent oil pressure...
It adjusts with a hand turnable screw, close to the choke pull, on the left side...

The idle should not sound like it's racing,.. but not so low as to be loping or stumbly...
Smooth and steady,.. a little high is better than a little low...