I am a newbie to this board and feel fortunate its here as a great resource. Thanks in advance for your generocity and knowledge. I run in South Florida primarily salt water and am diligent about flushing with fresh water using the earmuffs. On my last trip out experienced a mild knocking noise. Came in and found quite a bit of oil in bilge...creamy tan floating on water. Using a flashlight found a gaping rust hole (large enough to fit a nickel through) in the timing gear cover completely exposing the gears. Im assuming the knocking noise that brought me in for the day might have been a low level condition. Been bummed for the weekend concerned about the extent of damage entolled. Whats caused this? Surprisingly, the oil remaining in the crankcase appeared normal in appearance. Did this breach wear from the inside out or the the reverse? The black enamel paint seemed flaking off. Is there an alternate material available for this cover? Thanks again.