First time user. I have a 1982 eagle 1 moped I'm having problems when I go full speed for awhile the engine stalls. If I push the primer knob in I can get it to start again. At slow speeds it doesn't do it. I took the carb off and it seemed like all the things were free of any objects unless I'm missing something. I was wondering if it could be carbon build up in the exhaust? When I put my hand over the exhaust not a lot of flow, but then again I don't know how much should be there. Any help would be appreciated.