Scirocco Register

I've got a 1.8 overbored to a 1.9, with a weber 32/36 carb at the moment. Runs perfectly apart from then the engine speed is somewhere between 2000 and 3000 rpm, I then there is a small loss in acceleration in this engine speed band and the car starts to kangaroo slightly, although its nothing serious. Could this be just from the carb not being levelled properly and running too lean?

any advice would be greatly appreciated

My first thoughts are that the mixture is too lean.remove all the plugs and examine them for glasing/soot etc, this may reveal any mixture problems.also pinking when hot will also indicate a weak mixture.