Sounds like you need a service kit or, better still, just get another carby. Everything can seem OK when you examine it but the problems persist. As carbies age and get problems, they can be impossible to get right again no matter what you do. Many people just get a new one. Try a service kit first, if it is cost effective. That should work.
Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!
