If you can stomach all this reading and absorb and understand it all ...you could become a DellOrto expert! Be sure to see the information on the floats, it does pertain to Airheads, this is in section 3.2.2. See also near the very end of the long article below that you are reading, where there is my information on the pump setting and float setting, as pertains to BMW Airheads specifically! There are hints there too! The following information article came from, I was told, the .startwin.com site, and was sent to me in a zip file, which I have unzipped, modified, and put below. I have been unable to find the author or person who might, or might not, have copyrighted this information, so as to gain official permission to place it here. This article, whatever its original source, now appears to be public property. I tried to make sure about that, so, on 10-06-2003, I sent e-mails to van Star Twin Motors, the Startwin.com folks, asking about use and copyright. There has never been a reply. I last viewed their website in November 2017, and there is nothing about the carburetors. I have added my own comments to the article prefixed by ***, and underlined. I have corrected many typographical errors and misspellings in the original article ...and changed to U.S. type English spelling and usage. I have also eliminated some in-article hyperlinking, etc. There are places that my comments now are not all that clearly identified, as I wished to eliminate red color I used in earlier versions of this article, which resulted in gaudiness and an unprofessional look to the article; so this latest version generally uses asterisks and underlines for personal comments by me as well as for normal emphasis. I have also modified how the original's photos are formatted and placed, and added borders, and I also prevented wrapping of text around the photos. The following informational article can be quite useful for those trying to understand how any carburetor works. While the information does not deal directly with Constant Velocity carburetors, it does deal with needle & slide carburetors, & a vast percentage of the information applies to all types.