I noticed slight cracking on the inlet stub rubbers so replaced them but also replaced the 13 rubber seals in each carb with Viton seals. Ethanol in modern fuel is attacking carb rubbers apart from general age deterioration. At the same time I replace the emulsion tubes with Factory Pro, although there was only slight marking on the originals as there's only 11,000 miles on them. The main jet seals disintegrated when I removed them and the cold start seals were cracked and perished and drawing air.
Transformation! Now starts instantly on 2 cylinders and fast idles around 2500 rpm. Idles sweetly at 2.25 turns out on the pilot screws and during a quickish run down to the ferry for the NW200 (late for the ferry as usual) with a couple of indicated 120 on the clock, it returned 55 mpg and over 60 mpg at lower speeds in Ireland. I'm as happy as fcuk and thoroughly recommend a Brit out in Thailand called Blair McIntosh for his enterprising company producing seals for dozens of carbed bikes. He's also on here as Maelstrom. He also produces great photo "How to" on his website
http://www.litetek.co/
