Maintenance All Articles


Onan genset spewing black smoke

Question: I have a 4-kW Marine Onan genset with 600 hours on it. If I let it run for a lengthy period it produces so much black smoke that a residue discolors the hull around the exhaust port. A year ago, I cleaned the heat exchanger and installed a new raw-water pump. There are no overheating issues. Do I have an injector or rack problem?—Charlie Carpenter, Morristown, New

Noisy Engines

Question: I have a pair of Detroit Diesel 6-71 TIBs in my 1990 Ocean 48 Super Sport. I love both the boat and the motors, but the Detroits have always been loud at the exhaust end of things. As I grow older, this noise is starting to bother me, particularly at times when I have to shout to be heard on the flying bridge at cruise speed. Muffler companies tell me that modern

Garmin’s Tip of the Month - November 2010

To loosen a sticking oil filter that you can’t get to unscrew with a standard filter wrench; simply attach a hose clamp around the filter’s base, close and tighten it, and, after positioning a flat-head screwdriver sideways against the screw housing of the clamp, gently tap it with a hammer. I’ve had success with this method on more than one

Labor of Love

The 30-foot Carver Santego was for sale and up on the hard. From a distance she looked gray and tan instead of her original white with navy and black trim with...

Twin Engine Temperature Disparity

Question: I have a 1994 Mainship 31 with a pair of 315-hp Yanmar diesels with 2,000 hours on them. While running at full throttle (about 33 knots) for five minutes, the starboard engine temperature creeps up enough to set off an alarm. If I ease ‘er back to half-throttle, the temperature returns to normal after a couple of minutes. The starboard engine has always run a bit warmer

Algae On My Racor

Question: While performing routine maintenance on my Caterpillar C7, I was surprised to find a substance about the size of a quarter at the top of my Racor—it looked like algae. There was no water in the bowl, and the engine-mounted filter was found to be clean. My Cat runs fine now and I would like to keep it that way. I am getting a lot of suggestions from friends as to what

PMY TRIES... Nautic Air

It was an interesting suggestion, really.

Some weeks before, Heath Schuman of Nautic Air had UPS’d me an experimental version of his portable NA20 air purifier to temporarily try out on my trawler Betty Jane. I’d placed the thing on the dining table in Betty’s saloon straight off, plugged it into a nearby 110-volt outlet, and after securely closing all

Battery Blasphemy?

A contrarian take on battery replacement

All batteries have terminals and cable connectors that need to be periodically cleaned, preferably with a battery brush. I’m guessing I’m in the same boat as a few other folks these days. I’ve got three marine batteries salted away aboard my trawler Betty Jane...

Walker Engineering

Walker Engineering has been making diesels breathe better for more than two decades.

I used to crew on a 43-foot sportfisherman that was powered with twin 625-hp Detroit Diesel 6V-92s, and those engines were tank-like. In fact, the current owner of that boat has 3,000-plus hours on those original motors and they’re still going strong. But after

Vinyl Fever

It was astonishing, really—the near-total absence of useful information on the Internet concerning the renovation and/or replacement of marine vinyl cushions. Sure, there were plenty of canvas and upholstery shops listed and some were even conveniently near where I keep my boat. But the related Web sites were pretty unsophisticated and, when I telephoned them, the results were often less than

Yacht Restoration

Any boatyard can refurbish an elderly vessel, but where do old yachts get new lives using traditional techniques? The answer is the Newport, Rhode Island-based International Yacht Restoration School (IYRS), a non-profit organization that’s devoted to teaching boatbuilding and boat preservation the way it was once done. Indeed, IYRS students and faculty focus solely on bringing back to life

Professor Diesel

Q. I have a 2003 Sea Ray Sundancer 420 and am moving from the New York City area to Florida soon. Do I need to do anything different in Florida in terms of boat maintenance? I am especially concerned about the warmer waters down there and the algae growth in fuel tanks I've heard so many bad things about.


Dan Markow
North Haledon, New Jersey


Back to Basics

Fort Lauderdale's International Yacht Training offers a true hands-on dieselengine course with small class sizes.
Instructor Hartley MacDonald lectures to his students during an in-class segment (the author is at right). The course is five days long.

The Applied

Nautic Air Module - Got Allergies?

As an unabashed booster for boats and boating, I’m a tad amazed to find myself admitting that we boaters have a wholly invisible but smelly problem: onboard air quality. Consider my own 21-year-old, meticulously maintained trawler Betty Jane. Like lots of other vessels, she mostly gets used on weekends, and throughout any given weekend, especially during the summer, she’s likely to be almost

Jabsco Oil Changer

When my buddy Bruce said he had a like-new Jabsco Porta Quick oil changer he’d give me for free, I was happy. When I discovered the unit sells for $209.99, I was ecstatic.

The Porta Quick is a 14-quart plastic container/reservoir with a 12-volt electric impeller-type pump on top. A cord with alligator clips supplies battery power, and a toggle switch

Toss the Sawzall!

So a guy walks into a boatyard and says, “Hey, I gotta have a bow thruster.” In a few days, an open-ended job begins, with the bill contingent upon the yard’s hourly rate, expertise, and the man-hours worked. When the guy returns he finds his boat starring in a veritable horror show. A couple of first-time thruster installers have blundered into a foam-cored transversal while cutting a hole in

Swap or Not?

I explained to Joe Galati of Galati Yacht Sales that PMY was looking for a cruiser with incandescent or halogen lighting that we could swap for LEDs from Imtra Marine. We had four objectives:

The Creepin' Crud

Like lots of folks, I’ve got two diesel powerplants onboard, one for propulsion and the other for auxiliary power. And just a few months ago, the latter began showing signs of the creepin’ crud—it was overheating, sounding hoarse, and exhaling a greasy gray smoke under load.

The most telling symptom, however, seemed to be that the cooling water that was supposed to be

Wax On, Wax Off

Remember “Wax on, wax off?” It was Mr. Miyagi’s discipline-building anthem in Karate Kid. For years, I figured it was merely a figment of some movie maker’s imagination—it couldn’t be applicable to boat detailing, right?

Wrong! As part of my campaign to do my maintenance chores myself, I recently detailed my trawler Betty Jane and made her literally sparkle. But I had to cheat.

How to Break in a New Inboard Diesel

I’ve just purchased a new diesel inboard. What’s the best way to break it in without damaging it? -- Walt Reid

Most manufacturers list procedures for break-ins in their operations manuals. Stick with these but also bear in mind the following routine. Remember, the first 50 hours of operation can significantly affect your diesel’s life expectancy.

Examine the basics: Look for

The Bottom Line

Although I’m loathe to acknowledge my naivet concerning such matters (especially since I’m 61 years old and have owned boats all my life), my approach to in-water bottom cleaning was plain as dirt—if not downright cavalier—until recently. It went something like this: When growth on chines and running surfaces slipped past the faint-slime stage, I’d simply dial up a marina-recommended dive

Walking the Plank of the Charles W. Morgan

Keeping a 19th-century whaling ship afloat requires a combination of old-world craftsmanship and new-age planning, especially when that ship is the Charles W. Morgan, the world’s only surviving whaling...

Maintenance Headache

Maintenance issues are constantly stalking boaters. The simple fact is that on a boat stuff breaks and things leak. Boats are complex mechanisms with dozens of systems and hundreds, if not thousands of components. But three issues seem to account for the majority of problems afloat. Here’s what they are and how to deal with them.

Arguably, the most important component on your boat is her

Confirming continuity

An inexpensive multimeter like this is one of the few tools you'll need to verify the integrity of your boat's bonding system.  It’s a fair bet that every PMY reader knows about galvanic corrosion—or at least the basics of it: Drop two dissimilar metals into...


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