That's an interesting question. I know it's been awhile, but I'm not sure how long. So I researched entries from kz1300.com and found entries about having the carbs rebuilt almost 3 years ago!. While I was looking I found that I was having issues with cylinders 1&2 indicating a carb problem. It turns out that the float was stuck on the left carb, and that I requested a new float from Jack at oldschoolcarbs.com. This was after the rebuild.
I happened to dig around in my 'parts bin' and found that I have a brand new float valve in it's original package from Jack. So now I'm wondering if I actually ever replaced the float, or if he sent me two of them? Damn, old age sucks.. I got KRS real bad.
I'm 'guessing' that the float was working back then, and so I didn't bother to replace it. Crap! I wonder if that's been my problem all along!!
FYI, I can't seem to find any of the Gunson G4074 anywhere it the U.S.? The only one I've found it the Gunson Colortune for 12MM + the 14MM attachment for $99.95 US on Amazon and Ebay. Seems kind of pricey.