The book called for changing the oil and filter at 20 engine hours. I may have gone over that a bit............say to maybe 40 hours.
The filter was filthy and full off some kind of fuzz or fibers along with some very fine metal shavings which is to be expected. The transmission still shifted VERY stiff when not fully warmed up and even then, not very easy. Everything was pretty much straight forward and by the book. I decided to use Amsoil 15W-40 Heavy Duty Marine Diesel oil. Now it shifts like butter. Amazing how much difference some clean and good quality oil makes. I never would have believed that in and of itself would have made that much difference. Anyhow it is like an entirely different machine now.