This past weekend we were having difficulty tuning an Webra 50 GT. It has the TNII carb. It keeps getting fat and dieing in the midrange at the crossover point for the needles. It idles great and has quick transition from Idle to WOT but at that particular point where the needles cross it starts to get fat and dies. This engine is two years old and has run well in the past. I am thinking I has something to do with the carb maybe the High or low speed needle might have been smushed. Any ideas would be appreciated.