Decided to try a different oil to combat the low viscosity that I was having with the Yamalube 10w-30. Went with West Marine 4 stroke 10w-40 this time. Unfortunately, I don't think the large amount of idling we do helps these motors, but its the nature of our work. Never noticed a significant rise in the oil level of the port motor though. I did skip doing an analysis on the last oil change as it was a short interval and went ahead and did this latest one which was closer to 100 hour interval.