Hey all, new to forum and Harleys. Bought an 05 roadking custom with about 14000 on it. Has Rhinehart true duals and a screaming eagle efi tuner. Been noticing some popping whenever I downshift and even now upshifting. Was reving a bit high at light, goosed throttle and bike stalled, started right back though. Plugs looked pretty white around tips, any ideas?