Hi there,
I have a 2004 GS500F. 
OE stock air filter
9" stubby Delkevic stainless exhaust with no baffle in.

It has run lean since I got it but recently started requiring me to twist & hold the throttle while fully choked to start it and then it wouldn't idle up to the normal 4k, only like 1-2k.  The next day it then started pissing gas all over my driveway.  It appears to be the floats sticking and the gas overflowing into the airbox and down the airbox drain hose onto the ground so I'm about to tear apart my carbs and clean things up and replace things as necessary. 

I ordered a jet kit online from Sigma 6 racing and after giving them my bike info I assumed they'd just bump everything up a size from stock, but the jets they sent me seem like way too much of a jump for a stock air filter.

Stock for 2004 is Pilot 17.5, Mid Main 60, Main 130
They sent me 22.5-mpk jets for the pilot jets, Mid main jets of 74-msd and two sets of main jets.  135-msd and a set of 140-msd in case it was still too lean with the 135. 

For those more experienced than me, will 22.5/74/135 be too rich?

I didn't get any responses so I installed the new Jets but I am still waiting for my other parts to arrive before I button it up and try to tune things. I guess I'll let you know how it goes.

The instructions from that racing company also recommend shimming the needle on top. I guess for now I'm going to hold off on that because I can always do that later without taking the carbs off the bike.

I'm posting this here in case someone with a similar setup searches the forum.

2004 GS500F
new stock OE air filter
Delkevic stubby 9" slip on with no baffle in

What works well:
pilot jet: 20
mid main: 60
main: 130
mixture screws 2 1/2 turns out
two #3 washers as shims under needles

Public Service Announcement: Stay away from 6 Sigma Racing jet kits. 
Thanks to The Buddha for letting me bounce my situation off him.