Recently doing my pre winter tune up. Removed plugs; upper looked ok, bottom coated with very dry, brown powder (almost like dried up brownie), looks like a lot of rust. Can that much moisture get passed the fuel filter AND the carbureator? I use my outboard almost daily ....I usually tilt it up overnight etc..Is there a possibility that over our wet winter the humidity worked it way up the h2o intake, passed the impeller and condensated in the engine and caused the combustion chamber/pistons to rust? Thanks