[Derek]

In addition to Shazaams comments I'd consider replacing the emulsion tubes (needle jets). If they've never been changed at 40K they will be shot by now. Over a period of time the needles wear a groove in the jets turning them oval. Symptoms are a rich mixture and lumpy low speed running. I changed mine at 21K and it transformed the bike's behaviour at low speeds and around town, also picking up much more cleanly.