I have two tractors with exhaust pipes that go straight up from the hood. When I bought them used, they had spent their life with the pipes open to the elements. It never occurred to me that there was any risk or danger of starting them up after it rained. Eventually, the mufflers rusted out, which was expensive, so now I put a coffee can over them when I'm not using them. If I forget to put the coffee can over it, and I'm surprised by a heavy down pour, I just start it up like normal and get to work.
I'm at a loss as to what the issue is?