Be careful, take pressure hose off of pipe, blow in it like you are priming engine, you will hear if air is escaping. My experience with air leaks has usually been the tank cap o-ring, and high speed needle o-rings. The carb kits from Traxxas are 3 dollars, and come with the o-ring installers, and ful instructions to rebuild the carb, you will need a pick to make it easier to remove old o-rings.....Oh, do the above procedure with an empty tank, just in case, nitro fuel, is not only poisonous, buts tastes terrible too!