Ramelen1, I had a problem with black oil while breaking in my
Tower 75 engine, and found the problem to be a loose end cap
on the muffler. It was loose and vibrating and rotating around
causing the aluminum to wear, turning the oil very black. After using some lock-tite on all the threads and tightening
everything up real tight, the problem was solved. I suspect that
is all that is wrong in your situation with your Tower 61. Good
luck.