The white stuff looks like the BVM ceramic paste/coating that has blown into the pipe from most likely a hot start or the misalignment of the turbine. Is your engine in a bypass? Do you have the hot section coated with this ceramic paste? I had the same issue but mine was from a hot start in a BVM Bandit MKII bypass.
Last edited by DrV; 12-04-2016 at 08:15 PM.