I had a very close external inspection of my left side carburettor/induction manifold - found what looked like fuel residue, around the threaded end of the balance tube fitting> manifold. Removed & refitted with sealant. This may have been the small air leak, causing a lean fuel/high EGT condition when reducing power (increased vacuum).
Won't be able to test fly, due to wet weather making airfield unusable, for at least the next week
