Ask The Experts

Solutions from the BoatUS Tech Team

Photo of a ground plug

Should I Install Engine Heaters For The Winter?

My 30-foot Tollycraft is moored in Oregon. What are the pros and cons of installing a block heater on each engine? I'd like to protect them from freezing this winter and keep moisture from getting into the oil through condensation. Could this create electrolysis?

Don Casey: Leaving anything plugged in on a boat connects the boat to all other boats also plugged into that circuit, with the attendant risk of electrolysis. You can greatly reduce the risk if you equip your boat with a galvanic isolator that will prevent stray current in the water around your boat from finding ground through your shore power wiring.

I see no problem with the use of block heaters. However, keep in mind that extreme weather often results in power outages, so that when you need the heaters most, they may not work. Using the heaters to make cold weather kinder to your engines is a good idea, but depending on them to prevent a frozen block is high-risk behavior.

Cracked In Connecticut

I own a 2003 Stingray with a 5.0-liter engine. This year when I attempted to start it, it wouldn't crank. The engine appears to be seized. When removing the spark plugs, water comes out of a couple of spark plug holes. Even with the plugs out, it still won't turn over. Any ideas?

John Adey: I think you have a classic cracked block or head. You're in Connecticut; did you or your mechanic do a thorough job of winterization this year? It sounds like water was left in the cooling system and the head or block has cracked, leaked the water into the cylinders, and rusted the piston rings to the cylinder wall, causing the engine to seize. There are "freeze out" plugs located on the sides of the engine block (approximately the size of a half-dollar); sometimes these plugs "blow out" as the water expands while it freezes – one of the first indications of the block freezing. The plug should be lying in the bilge if it blew out. I think you're looking at a new engine. Sorry.

Cold In The Ditch

We're thinking of making our first trip down the ICW, from the Chesapeake Bay to Punta Gorda, Florida. We can't begin our journey until the week of October 5th. Is this is too late?

Tom Neale: We've done this trip as late as the end of December. Each season is different, but leaving the week of October 5th is not too late. We prefer to leave mid to late November, to allow the hurricane season to wind down. You probably have reverse-cycle heating and air-conditioning, which will work from your generator or from shore power. You'll find many good marinas where you can tie for the night, plug in, and keep warm. If you anchor out overnight, I don't recommend running the generator for heat while you sleep. Just bundle up and take extra blankets. Have a great trip.

Fixed Fire Extinguishers

In renewing the coverage on my 1987 Silverton 34X, my insurer noted a missing inspection tag on the automatic fire extinguisher in the engine room. The wording in their letter says, "It's a federal law that these systems are checked and tagged every year in order to maintain their USCG approval." I'm not saying that's a bad idea, but in 31 years of boating, I've never heard that it's a federal requirement to have them tested annually. Also, my boat doesn't have the remote "alert and ready" panel and I'm wondering why a previous owner would install the auto extinguisher and not the panel.

Don Casey: There's no federal requirement to have a fixed extinguisher system inspected annually on a recreational boat. However, if your insurance coverage is predicated on a fixed-extinguisher installation or if you're getting a premium discount, then typically the system must meet ABYC (American Boat & Yacht Council) guidelines, which does require a full maintenance check every year by a qualified fire-extinguishing-system service facility in accordance with the manufacturer's maintenance instructions. A tag should be attached, showing the date of such maintenance check.

The issue with Halon and Halon-replacement fixed systems is that they're similar to propane: A pressure gauge only tells you there's pressure, not how much of the agent is in the canister. The primary value of the "alert and ready" panel is that it warns you of a loss of pressure without the need to look at the cylinder gauge — often out of sight without a special effort. Having such a panel gives no additional information about the volume of agent in the canister.

Maximum Capacity

I have an 18-foot 1999 Bayliner Trophy Walkaround and the capacity placard is worn and unreadable. Bayliner responded to my request for a new placard with a letter listing the capacities and suggested that I keep a copy of this letter onboard to present to authorities doing a safety check. Will this meet the requirement for the placard listing capacities or will I be in violation? Can you help me get a real placard?

John Adey: You can't get a new placard from Bayliner, so your only choice is to have one made at a sign shop. The Coast Guard has a very specific format for the layout, color, and content of the label. Visit, and click on the "regulations" tab where you'll find the "Boatbuilders Handbook." In the section on "Capacity," you'll find the dimensions of the plate. Take this to a vinyl-graphics place with the numbers Bayliner gave you and have a new one made up. Don't be tempted to increase the capacity; Bayliner has tested and certified this boat with the stated number and modifying that could endanger those on the boat should someone operate it in the overloaded condition. Also, I inquired with some of my law-enforcement contacts; they assured me that the capacity letter will be sufficient should you be stopped on the water.(See our article on federal requirements on weight limits, Weight and Sea.)

Ghost Voltage

I have a 1989 Hunter 40 Legend with an electrical problem. The voltmeter in the main panel shows one to two volts when the battery selector switch is in the off position. No shore power is attached to the boat. All electrical connections have been disconnected, cleaned, and reinstalled with no change. There's no apparent loss of cranking power after several weeks of non-use. The selector switch is always left in the off position when not in use. Your thoughts?

Tom Neale: You may have a defective meter, particularly if it's the type with a needle. Sometimes as they get older, these will begin indicating voltage in the needle's resting position even though there's none. Check by turning the selector switch off and removing all wires from the meter. If you still get a "ghost" voltage reading, your problem is with the meter. If the ghost voltage goes away, you'll have to go through a long process of elimination to isolate the problem. The first step would be to test for voltage at the outgoing terminals at the selector switch, with the outgoing wires disconnected and the switch off. Start tracing back from there, using the process of elimination.

Radio Performance

I fish the Great Lakes, occasionally up to 15 miles offshore — too far for my handheld five-watt radio to reach reliably. My boat is a 21-foot open bow Bayliner. I want to install a fixed-mount VFH, complete with antenna. I don't want to over-buy, but I want one that will let me stay in touch with my fishing buddies. Any recommendations?

Don Casey: There will be very little difference in the power output among reputable brands of VHF radios. Where most installations go wrong is in selecting a cheap antenna or small coax. Choose the brand of radio based on reputation for reliability, not performance. Select their least expensive model that has the features you want. Where you want to spend a little extra is on the antenna and cable. The trick to good performance is getting all of the power the radio delivers out into the air, and that requires big cable and a good antenna. Do your homework here and you'll end up with an installation that will never leave you out of the loop. (For more information, see "Installing A VHF Radio" .)

Breaker, Breaker

I need to replace a circuit breaker/switch. The switch toggle is broken off and even though the breaker still seems to work fine, the survey says replace it. The original breaker is a 2.5-amp and all I can find for a replacement is a 5-amp. Is it ok to install the 5-amp in place of the 2.5?

John Adey: You're going to need to stick with that 2.5-amp breaker. The size of the wire and other electrical components in that panel all take into account that the circuit will not exceed the trip level of that 2.5-amp breaker. Increasing the amperage could result in excessive heat and potentially a fire. If I were the surveyor and came back to check on your installation, I'd write it up again. This is one area where you don't want to use the theory of "bigger is better"!

Overworked Outboard

I have a 1999 150-hp Mercury outboard mounted on a 20-foot Pro-Line CC. When moving through the water slowly, starting to plow a bit, the engine overheats. When up on plane or idling, the temperature returns to normal. What causes this?

Tom Neale: It sounds like the engine is overheating when it has to work harder. This could mean that the cooling system is marginal. This could be caused by the water-pump impeller going bad; or other problems such as corrosion with the water pump, a failing thermostat, corroded thermostat housing, or blockage in the cooling passages. Many things can cause the latter, ranging from debris, corrosion, or even a mud dauber's nest. Going slowly also forces less water into the passage leading to the pump, and if there were a restriction or other problem, the effects could be worsened. Check your indicator stream, and consider replacing the thermostat. Check the housing and whatever passageways you can see when you do, and then the impeller and/or pump housing. If you haven't yet done this yet on a 1999 engine, it's well past time. 

— Published: October/November 2011

Keeping Diesel Fuel Clean

Thumbnail photo of a diesel gas pump

Keeping fuel clean has always been the key to maintaining a healthy diesel. Here are four important considerations to keeping fuel clean:

1. Start by adding clean fuel, which means buying your fuel from a reliable source. Fuel that's been languishing for months in an underground storage tank is more likely to have water, rust, and even bugs.

2. Microbial bugs can't live without water. Keeping the tank topped off minimizes condensation. Check your fuel separator routinely for water, which can signal a problem that will need correction.

3. Check to see if your fuel distributor uses biocides in its fuel. If not, add a biocide at the recommended dosage.

4. Change filters at least annually. Slimy, smelly filters are indications of a microbial fuel infection. If filters, especially secondary filters, look dirty, consider having your tank emptied and cleaned. Otherwise, you'll be fighting an uphill battle.



Meet The Experts

Don Casey

Don Casey
He's been one of the most consulted experts on boat care and upgrades for 30 years, and a panelist on our "Ask The Experts" website for a decade. He and his wife cruise aboard their 30-footer part of the year in the eastern Caribbean. His books include Don Casey's Complete Illustrated Sailboat Maintenance Manual, and the recently updated This Old Boat, the bible for do-it-yourself boaters.

John Adey

John Adey
The VP/Technical Director for the American Boat & Yacht Council (ABYC ), John grew up boating. He's been in the industry since 1990, with experience from a yacht brokerage and boatyard to owning a marine supply store. He and his family sail their classic 1976 Irwin ketch, a boat he completely restored. John is a trusted source for technical information for industry professionals.

Tom Neale

Tom Neale
He's maintained, lived aboard, and cruised long distance on boats with his wife and family for most of his adult life. He can take apart and fix almost every system aboard a boat, has written two books, filmed a two-set DVD on East Coast cruising, written for top marine magazines, and has won seven first-place awards from Boating Writers International and many awards for his technical writing.

Bob Adriance

Bob Adriance
The editor of Seaworthy, the damage avoidance newsletter of BoatUS Marine Insurance, Bob has written hundreds of articles on safety, loss prevention and causes of boating accidents. His 2006 book, Seaworthy, Essential Lessons of Things Gone Wrong, is based on 20 years of real claims files. He's owned Folkboats to J-Boats and currently sails a 36-foot sloop.

Lenny Rudow

Lenny Rudow
One of the most experienced technical writers in the marine business, and an accomplished fisherman, Lenny has a thorough understanding of modern marine electronics on both technical and end-user's levels. He's written five books, and won 18 Boating Writers awards and two awards for excellence from the Outdoor Writers Association. For several years running, he's also been selected as a judge for the NMMA Innovation Awards.


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