I gave some guidelines/information on the "Mysterious parts" and "Running a 16H/B4" pages of the website.
There should be enough info within the "normal"running requirements to help you solve the problem.
It indeed suggestes to much air/ to little amount of petrol at higher throttle setting.
First check if all parts are as proposed, and work from there on as given in the AMAL text.
Its a job requiring patience but if the carb is fairly OK it should work.