That's Not Too Bad
Keep in mind that a quart every 40 hours is equivalent to about 2000 to 2500 miles on an automobile. It may be a little more than you would like, but it is not an inordinate amount. I do not think I would worry too much about it. The Yanmar in my P42 used a quart in 110 hours this summer. What I find is that it will use nearly none until about 50 hours and then it starts to use a little after that. It just goes to show that clean oil works better than dirty oil.
