When you get these engine the computer is set to double oil during
break-in.Your comsumption figures seen to fall into the double oil range. As
I understand, break-in is not a set number of hours but depends on how many
hours at what speed. But for a rule of thumb, 100 hours should be plenty to
satisfy the computer. Also after service work anybody with a Mercury DDT
(scan tool with Merc programs) can reset the double oiling. This would be
the case if a new powerhead was installed or an overhaul was done by someone
with the proper shop equipment. The Merc SmartCraft gages can tell you the
hours or you can have someone plug it into a DDT to get the hours and
break-in status.
Bottom line, if you don't know the break-in status you can just put some
hours on it and see if that "fixes" it. Don't worry, be happy.

--
Ron White
Boat building web address is
www.concentric.net/~knotreel