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Diesel 101 Page 2


Loosening the cylinder-head bolts requires a long wrench and some good ol' muscle.

During the one-day class, we spend most of the time in the classroom. Berlin takes us through the basic parts of a diesel engine, explains the theory of operation, and reviews common errors that many boaters make when maintaining their diesels. He tells us of owners who try to save a few bucks by using belts until they disintegrate, change oil without changing filters, don't check or change gaskets, and use impellers until the blades are worn away. "When an impeller shears away, those rubber pieces are going to end up in your engine, in your heat exchanger, and other places that are going to be difficult to find, and you're gonna need to find them all. You won't be able to, and you'll call us," Berlin tells the class. He explains that by trying to save money, these boaters actually end up spending more than if they'd simply taken the simple, inexpensive precautions. To drive his point home, Berlin has littered the classroom with a bunch of heavily damaged engine parts that are the result of poor maintenance.

The two-day course also includes classroom instruction, but we spend about 60 percent of the time actually working on engines. This turns out to be my favorite part, a feeling that is shared by everyone. On the second day of this class, we find identical Yanmar powerplants at our respective stations, ready to be tinkered with. Berlin walks each of us through the lubrication and fuel-injection systems, and provides us with schematics for each engine. We disassemble seawater pumps, remove impellers, and reassemble everything. Berlin offers advice but also allows us to linger as long as we like on each maintenance project.


Reading a torque wrench (left), disassembling heat exchangers (middle), and changing fuel filters (right) are some of the classroom topics.

By the end of the second day, the more confident students, including me, have disassembled heat exchangers, bled air from fuel systems, and followed torque specs as we remounted cylinder heads.

On the last day of our instruction, Berlin reminds us that a diesel that's regularly maintained and properly operated should enjoy tens of thousands of trouble-free hours. After my three days with him, I'm now confident that I can do just that—plus handle the occasional crisis if one comes up when I'm miles from my homeport.


Instructor Larry Berlin

The name Mack Boring comes from the company's founder, Ed McGovern, Sr.'s surname and his favorite tool back when he founded the company in 1922: a boring bar for cylinder blocks. Once located in Newark, New Jersey, the company's present location, a five-acre, state-of-the-art facility in Union, New Jersey, Mack Boring is a family business, with three generations of McGoverns having worked under its roof. The company other has branches in New England, the Midwest, and the South, and each of these locations hosts its own diesel classes several times a year, all of which are taught by Larry Berlin, who also conducts seminars for women and owners of specific boats all over the country.

Mack Boring
(908) 622-5364

This article originally appeared in the January 2007 issue of Power & Motoryacht magazine.