I did some investigating on the clear pink vent tubing that powersport OEM's and or Keihin uses on their carburetors from the factory. Oddly enough, it was a little difficult to find. Most of what you will come across when looking for vent tubing are pre-cut pieces, which is annoying if your trying to have all of your tube ends meet together at the same point for a clean look.
I ended up finding a source that supplies the big 4 out of Japan. I ordered 2 reels, the minimum length you could purchase is 50 meters, or 164 feet.
Ive got 4mm I.D. 7mm O.D. for every connection on your carb besides the float bowl overflow.
Then 3mm I.D. 5mm O.D. for the float bowl overflow.
Once it arrives I will do some measurements and cut one long piece of each size to redo a set of carbs or one carb if you specify. Probably 10 feet of the thicker tube and 3 feet of the smaller stuff? Just rough guess right now.
$30 for both carbs plus free shipping in the states, or $20 for one.
Ill post pictures of the stuff when it comes in. If your interested shoot me a PM or comment and I will reserve you some.
Thanks