I have to agree with Stuart! It sounds like something has lodged the needle valve and not letting gas into the carb. Mine had an air leak but all it did was make it run and idle rough: it would still start. Do you have a gas filter in-line before you get to the carb? If so, did you remove it when you took the carb. off? The gas filter goes on only one way. If you have one and removed it, it may be possible that you put it back on backwards and this maybe the cause. Hope this helps!
John
