I just purchased a boat with a 99ish 25hp Johnson 3cyl 2stroke. I know it has been sitting for a number of years so I pulled the carbs cleaned them all and when I went to change or check the lower unit oil it appears to be filled with grease. Very strange but I guess my question is what would be the best way to flush it out? Maybe kerosene or varsol or diesel? Not sure what the best way is to do this, never seen this before and a little concerning. Any help would be great.