Hello all. I have an 84' oday 30 sloop with a universal M3-20B. About a week ago I noticed that I was giving it more throttle when in gear and the engine didn't repond, wouldn't go above 2k RPMs. Runs fine in netural but under laod it dies down and emits a nasty black looking soot in the exhaust water. Any suggestions? Any one else have this happen?