replacing the old Perkins 4-108. I had it rebuilt in Mexico 3 years ago and it runs great but now it's starting to develop the old oil leaks again. They say a Perkins will run forever as long as you don't mind "managing the leaks". I get 6 Kmpg pretty much always unless it's punching into a strong wind and chop. Then I've had it drop down to as low as .75 Kmpg. A new motor would go along way towards better mileage but I can buy a lot of fuel for the 16K he wanted to replace the motor. In the end I had him replace the gasket. Of course it was the one behind the motor mount plate which required removing the timing cover, both water pumps, the injector pump, manifold, fresh water reservoir, valve cover and tappet train, and finely the plate itself. The new gasket took about 20 minutes to clean off the old and install the new. Of course nothing ever goes as planned and he dropped the injection pump and broke the tower so the pump had to be rebuilt and tower replaced. That cost a bit less then "$400 bucks" but that's not on me. It took the guy about 12 hours work for a $5 dollar gasket. Has anyone else replaced this gasket? How long did it take? It looked like the fellow was working all of the time and I had used him for a prior problem and he seemed competent. He charges $100.00 an hour and gave me an estimate of 8 hours plus parts. We haven't settled up yet so it will be interesting what the final bill will be. The job was suppose to be 8 hours and it turned out to be about 12 spread out over 5 days. Some of it was the broken injector pump and some of it was the fact that he put in a gasket backwards and I wasn't getting any oil to mu sending units to tell the regulator to power up or the alarm bell to turn off once the oil pressure developed. That took me a couple of hours to chase down before he got back down to the boat. He had it fixed in an hour which was pretty quick but it still cost me another day off the water as we had planned on heading over to Mission bay for a couple of days. What do you guys feel would be a fair number to agree on basis on the above???