You should find a guy at your field. What you may have to add is a tube to the diaphragm on the carb. If you have not done this before you may need to see it on someone’s plane. The brass tube is silver soldered to the Float Diaphragm plate and a piece of silicone tubing is run into the firewall. The firewall should be sealed. It sounds like you are way lean. Can you post a picture of the bottom cowl cut-outs and the carb exit?

Go to Greater Southwest Aero Modelers web site look for Tech Site and look up Walbro Card Tune Up and Illustration

This has some tips on how to adjust the carb.

http:tech.flygsw.org/walbro_tuneup.htm


good luck