. Also pressed into the carb are two welsh plugs which respectively each cover the high and low speed fuel jet chambers. Underneath the high speed welsh plug is another filter screen most people do not know about. It is retained to the chamber floor with a small ring and the welsh plug has to be removed to gain access. Dirt and crud can get past the first screen located at the front section before the metering diaphragm needle. Rys....is this where you found blockage? Now on the transtion...some engines will hesitate when slamed open. Just do not slam it open. You might try and richen up the low speed needle a tiny bit. Also if a engines idles to long...they will load up and have to clear up on the quick opening. I think you are very close. The only thing I wonder how is that engine going to get good cooling air with all that carb and adapter up front. You may have to make air control metal-work!!! Capt,n