have you got the standard air filter on it?and is in good condition with no holes in it?you may be able to sort it out by raising the needle in the carb slide by putting th circlip on the needle at the slot nearest the pointed end of the needle,the problem you have is a fuel problem either the carb or the fuel tap and also it can be caused by water in the fuel.try draining the carb off to it has a small screw in the side at the bottom of the carb this will let any sh*t and water out if you undo it for 10 seconds then do it back up again.good luck
adam bike doctor, September 2006