Since the last post I have stripped and cleaned the carb. which has at least made the bike rideable, but I am still having a problem with idling.

If the throttle has been shut, the engine will try to die, if not idling very very slowly. Sometimes it will cut out, but when restarted it will idle perfectly normally.

Does anyone have any ideas how to solve this?

Thank you very much

Can anyone help?
I bought an LF250 in October Last year, and quite frankly I love the bike to ride, as it is so comfortable, but mechanically this bike has been a nightmare.
1 month after buying it I had to replace all of the pipe clips as the old ones were leaking, and letting air into the fuel system, and causing poor running., but it still would not run right.
Out of final frustration I then took it back to the importer in England, who replaced the complete fuel system, which then made it run lovely.
However recently I hvae again expereienced running problems:
1) When cold the bike starts on choke but will not rev, but if not tool cold it will start without choke, and then runs fine.
2) I have tried adjusting the mixture, 1/2 turn in which seemed to remove a slight flat spot, but trying to run the bike tonight, I have found once again the bike would not rev when cold on choke (but started and ran on tickover with choke when cold no problem).
When taken for a run once off choke, it kept trying to cut out as soon as the throttle was closed, and having checked the plugs when i got home they were very sooted as if the bike was running rich, but the carb have notbeen touched since the last time it was used when it ran no problem at all. The only difference tonight is that the temperature is approx 2º C, whereas last time the bike was used it was about 8ºC. Does anybody know of choke problems etc, as i am coming to the end of my tether with this bike, which I have had nothing but hassle with from new?
Any other suggestions apart from putting a match to it are gladly welcome!