I have a BF45 I believe around a 1996 model that I did a water impeller install, carb pull and clean on about 1 month ago. I also replaced the motor and lower unit oil. I took the boat out for a short run and everything seemed to work fine shifted forward and reverse with minimal difficulty. This motor has never shifted smoothly normally grinds a bit going into reverse and clunks going into forward. This weekend I took the boat for a long run and when I stopped the boat was very hard to go into reverse so I stopped pulled the cover and I have what appears to be black oil in the bottom of the motor. Quite a bit of oil , it doesn't appear to be coming from the motor. Any ideas can this be coming from the lower unit to the top of the motor ? My motor oil is clear and the oil in the top of the motor is a dark color not clean looking similar to the new oil in the motor. Anyhow it appears to be a major leak idea's , solutions would be appreciated.