srm99... I did read the manual you posted. Please take a look at the site Greater Southwest Aero Modelers and go to the Tech Site and look for Walbro Carb Tune Up & Illustrations.
Link http//tech.flygsw.org/walbro_tuneup.htm

I have been around gas engines since the 80's when a local guy first put a Quadra engine in a scale plane, his name is Dario Brisighella, owner of "US Quadra". He had worked on the same problems we are doing battle over. This is not a new thing nor is it just a DA problem. I only mention Dario because anything I say or do has come from his earlier work and reading his book “From the Firewall Forward” . The above link is the next best thing to Dario’s book. This is how I set up all my gas engines and I do not have any problems. At this point I am going to follow the Airplane experts. As for the Walbro manual, I did read it over and if you could read Dario’s book and the info from the link. It makes sense to me. I am using the tube and the box. Sorry I am NOT attacking srm99, and I do not understand why you think everyone is attacking you ideas. I am sorry if I choose to take the advice of guys who fly gassers over someone who races go carts or runs chain saws. I would also recommend talking with the manufacture directly if you are having problems with your engine. As far as my DA 50, it is the most consistent running engine I have seen. Sorry if that bugs you.