Originally Posted by Tacomasailor
Hello How does one operate a pair of overly powerful engines at economical cruise speed when a single engine can provide all the needed power at a low RPM? The DeFever 61 needs only 73 HP at the prop to move at 8.7 knots which can be delivered by ONE engine at 1500 RPM.
Provided the PO did a good job of maintenance, those engines have lots of life left in them. You need not worry about the engines gumming up if you run them slow provided the oil temperatures are minimally 180 or so when cruising at about 8 to 8.5 knots.
For sure the Cat maintenance schedule needs attention, if the PO shirked his obligations because he was cheap or lazy, be prepared to spend an easy $8K having Cat do the required work, which is much more than an oil and filter change.
BTW, describe the DeFever a bit more, I 'm familiar with these vessels and could maybe make a suggestion or two. Feel free to PM me.