I had a carb overflow issue which I try to fix myself w/ a carb rebuild.  New o-rings and all.  Finally got her back together again, still the same problem, if not worse.  Could someone recommend a mechanic in the area (Cerritos, Long Beach, Norwalk)?  Bike has been out of commission for 4 months now, time to seek professional (at least more knowledgeable) help.  If someone is willing to give me a hand, I'm more than will to compensate appropriately. 

Try Prospeed in Lakewood--nice guys (Ian and Larry) that are real helpful and I'm very satisfied with the work they've done on bringing my '90 GS up to snuff.  They're number is 562-804-5017. 

Do your carbs floats actually float? That's an easy check. I've taken my carbs apart 6 times now just to keep them clean. I could help you out if you still need it. I live in Corona.

I had the same problem.........Let the bike idle and give it a few high revs, keep the bike running and turn off the gas to the petcock, then rev the bike to a steady rpm and let it run out of gas. Then start her up again with the gas on. Let me know if something improves. It's probably rust in the carb issue. I'd recommend a filter too.

Mine used to do that. You need a good needle valve assembly and your float height may need adjustment.

You should measure the float height levels too.

I had similar problems myself with overflow.
Check your spark plugs to see if they're fueling the engine correctly.