It's difficult to describe exactly what it does, because it is erratic.
The glow plug is new...and the fuel is new. Also the needle limiters are off. The bearings should be here in a few days, although I'm doubtful that is the problem. I'll go ahead and put new ones in since I have the engine apart. My next move is to seal the carb. Maybe some of that liquid gasket gunk (RTV?). Maybe a small ring of that stuff will help. I don't think it would hurt anything. And I may replace the whole fuel tank set up. This tank came with the kit and maybe it has a leak. I've applied pressure to the tank and it doesn't seem to leak, but who knows. I'm going to pull it apart tonight and make sure the clunk line doesn't have a leak that I over looked. Also I don't see any air bubbles in the line so I'm not sure that is it. I haven't noticed the engine acting up at a specific fuel level either. Its the same with the tank full or almost empty. AAAAAAh!!!!

The engine runs rich for 8-10 seconds at full speed....then peaks out for another 10-15 seconds.......then revs and bogs. revs and bogs....or sometimes it just bogs down and almost dies until I lower the throttle and save it from quitting. Nothing I do with the needle seems to change this. Doesn't seem to be a tuning issue as much as an air leak issue.