First chance you get, dump the Sullivan filter. They only work so-so for glow fuel and pretty not much at all for gas. Attached is a picture of a filter you should pick up a pair of. Saw and mower shops or anyplace that sells better gas powered yard and cutting equipment. One goes in your plane's gas tank, replacing the clunk. The other goes into the gas can, acting as a clunk/filtered pick up. Filters to 10 micorns and because of the felt will pick up the last drop of gas in the tank and break up any bubbles.

The carb looks complicated on the outside. In fact, it's quite simple. If you take one apart simply lay it out in the order a part comes off the carb. Note the orientation so that it goes back on the same way it came off. use a can of compressed air like those found at office supply stores to blow out all the tiny fuel passages. That is the area that is likely killing the engine when the throttle is advanced to high.