Check for Air leak?

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!

Other airleaks can develop along the backplate, the base of the carb, fuel line, fueltank, fuel inlet on the carb. An airleak can develop jus about anywhere air can get. Have you physically seen air in the fueline? If so it will allow you to narrow down the location of the leak. Grab a tube of high quality rtv and seal away. I seal everything I drive as the first truck I had caused me all sorts of tuning nightmares with airleaks. Havent had an issue since.