Sounds like the noise your hearing is just the fuel tank venting thru the evap cannister and back through the check valve. Thermal expansion after a good run , perfectly normal. I would loose the canister and the tank will vent freely, and you'll lessen the chances of the internal pressure swelling the tank if you have ethanol gas. The oil mist behind your cylinder is either the breather hose still leaking at the clamp or the o ring on the cam sprocket cover the hose connects to. It could also be from a spark plug tube o ring or valve cover gasket. If you look with a good light between the cylinder cooling fins you will see a little drain hole that drains the spark plug gallery, if you have oil leaking from there it's the plug tube o ring. ( most likely the lower one)It could also just be residual oil from the hose leaking that wasn't cleaned off. Had all the same issues with my 09. O rings and valve cover gaskets and the seals on the screws holding the covers are peanuts to replace and there at that age where it's time. I find it takes a good tight clamp on the breather hoses to keep them from weeping oil. dave
