Hi I just got permission to post. 

EDIT: Realized I never asked a question.  Should I be worried about riding this without getting it taken care of?  Not to far, just to my house.

The short, strange ping in the top end at 1k idle.

2002 GS 500 12k miles. 
It started up fine from cold but had problems idling without choke after warming up.  After the guy messed with it idle was steady.  Except now there's this noise coming from the top end at idle.  It's idling just above 100 and every 5 seconds the tach needle will wobble under 1k with a ping, about 4 pings with a very slight loss of RPM, and then back up to 1k sounding fine.  It is a rythym.  The ping is not resonating but it's not exactly faint.  The ping was still there when he throttled it up to 2000-2500 rpm. 

The guy says he's a certified suzuki mechanic working out of his buddies garage and did the 12k mile service with the valve adjustment.  Not including fork seals....

I've read other posts regarding gasoline, tipping it side to side, loose valves, plain ol normal intake noise etc...
I will try ALL those tomorrow.  ANY ideas welcome. 
The guy is looking into it without my asking which suggests it shouldn't sound like that. 

Soooo many adjectives with "ping" at the end so forgive me if I missed a post on "engine ping"

EDIT : http://gstwins.com/gsboard/index.php?topic=37436.0 is the most similar description.  I don't know about the technical etc but "intermittent ping" sounds about right.

Is this just a bad servicing?

Lean misfire ... sheite is clogged ... anyway if its really pinging you can kill it in a hurry.
Cool.
Buddha.

I agree with Buddha.  As I read your description I began thinking your pilot jets are dirty.  But it's not a ping.  Ping (detonation, or pre-ignition) happens under acceleration or hill climbing, not idle, usually in hot weather, and is caused by not enough octane in your fuel.  Your bike doesn't require high octane fuel.  You have a different problem.  Don't tell us you stored the bike for 3 months without putting stabilizer in the fuel, allowing your jets to become coated with varnish as the gas breaks down.  You will get 40 lashes with a wet noodle for that!  If you did, your jets are clogged, and you'll have to pull the carbs apart and clean them.  Ask Buddha about that, he's the carb guru around here.  Get ready to buy some 4mm screws!