BOAT ENGINE PROBLEMS ENGINE BASICS
'My engine sputters and coughs!'
If the boat engine hesitates when you try to start it or it runs rough once you get it going, check the spark plugs.
Make sure the plugs are properly seated on the cylinder head so they are sealed and adequately transfer heat. If that seems OK, then check the gapping of each plug ... generally, plugs should be gapped at 0.50 mm but check the engine manufacturer recommendations and adjust accordingly.
Should your plugs be in good shape then move to the wires. Make sure they are tight. Check for cracks and stiffness because both conditions mean they need to be replaced. Cracked wires can result in the spark plugs not getting enough juice. Also inspect the connections between the battery and other electronic systems such as the regulator and alternator. Make sure the connections are tight.
Another common cause of rough engine performance is excessive water or dirt in the oil or fuel. Dirty fuel filters or water in the fuel-water separator are indicators of this problem. (Click here for oil changing information.) There is usually some water in fuel to begin with, but when combined with condensation in the fuel tank the amount can become excessive.
In time, the water will separate from the fuel and settle on the bottom of the tank along with a bacteria-fungi laden sludge that was once diesel fuel. (Fuel is a perfect breeding solution for some bacteria.) Eventually, the dirty mix will find its way into your engine.
Use a fuel additive that contains a water dispersing agent and biocide to remedy the problem. Drain the fuel-water separator and change the fuel pump filters.
Have you checked your battery? Click here for Battery Info.
Return to top Remember, it's not a car ... don't substitute land-vehicle parts for marine vehicle parts. Marine parts are designed to operate in a water environment ... others are not.
Change the oil and filter regularly. This basic maintenance tip has saved countless engine problems.
When gasoline engines start they smoke to some degree, but once the engine runs for a minute or so there should be no excessive smoke. Excessive black smoke could mean worn rings, a fuel mixture problem or an oil leak.
BOAT ENGINE CARE & REPAIR
Boat Battery Basics
Corrosion kills batteries. If the battery has a white crystallized powder on top then it needs cleaning. If unchecked, the corrosive material will begin to drain the battery. A paste of household baking soda and water will remove the corrosion from the battery and wire connections. (Wear eye protection.)
Keep the battery in a dry, well-ventilated area of the boat.
Make sure water levels are maintained in dual-purpose and deep-cycle batteries. Use distilled water to refill. (Maintenance-free gel and starting batteries are sealed and should not be tampered with.)
Keep the battery properly charged. It is important to use the type charger recommended by the battery manufacturer. Overheating is easy, for example, if a gel battery is not charged a charger that regulates voltage and compensates for temperature.
Don't routinely run a battery down ... and never discharge below 12 volts ... batteries don't tolerate routine deep discharges and they don't recover well during recharging. (Use a voltage tester or "voltmeter" to check the voltage.)
Perform regular load tests. Batteries are rated by the cold cranking amp. Testers should be capable of applying a load that equals to about half of the battery's cold cranking amp. For example, if a battery is 650 amps, the tester should be capable of applying a 325-amp load. When testing a 650-amp battery, the testing amp load should be applied for about 15 seconds ... terminal voltage should be 9.6-volts.
Recharge the battery promptly after use to prolong its life.
BOAT OIL CHANGE
Boat Oil and Filter Change
Few maintenance tasks are as vital to a good-running engine than an oil change. Changing the oil and filter is easy and takes little time.
Here's what you need:
Oil ... gasoline inboard motors usually hold 4-7 quarts of oil.
Check the manual to determine the specs for your engine.
Oil siphon (a manual siphon costs about $25).
Clean rags
De-greaser-bilge cleaner
Thick plastic trash bag
Plastic container to contain drained oil.
Here's how you do it:
Start the engine and let it run for 5 or 10 minutes so to warm the oil.
Turn off the engine off and stuff rags in the bilge under and around the engine to catch any runoff.
Remove the dipstick and put in the siphon tube. Place draining tube in plastic container set aside for drained oil.
Smear some oil on the gasket of the new filter.
Unscrew and remove the old oil filter ... place in plastic bag.
Screw on the new filter and tighten.
Pour in all but about a half-quart of the new oil.
Start the engine to circulate the oil.
Wait a few minutes then check the dipstick ... add the remaining oil if needed.
Remove the rags from under the engine and place in the plastic trash bag, (Oily materials must be disposed of properly.)
Use a quality de-greaser to clean up the engine and surrounding area.
This is an ideal time to clean the bilge to ensure that no oil from the project remains in the hull area. Click here for top-brand bilge cleaner information.
OIL AND THE LAW
Federal Regulations
Federal regulations governing boating include adherence to the Federal Water Pollution Control Act and the Refuse Act.
The Federal Water Pollution Control Act hones in on the discharge of oil or other hazardous substances into the waterways.
The United States Coast Guard requires that a vessel's bilge be kept "reasonably clean." What's more, boat operators can face heavy fines should they pump oily bilge water out of the vessel and into the waterways. In fact, a boat operator can be fined for illegally polluting waterways if a even a small amount of contaminants ... just a visible sheen ... is seen floating atop the water near a boat. Fines have been known to exceed $20,000 for dumping oily bilge solution into the water.
Owners of recreational vessels are urged to equip their boats with with oil absorbent pads, bailer or pumps, and plastic bags to gather and transport hazardous substances, including oil, to an authorized reception facility. Most marinas and boat yards are authorized waste reception facilities.
The act also specifies that no person may intentionally drain oil or oily waste from any source into the bilge.
The Refuse Act prohibits discharging or depositing any trash, garbage, oil or other liquid pollutants into the nation's waters.
In addition, no plastic items may be dumped overboard in US waters, including synthetic ropes, fishing nets and plastic bags. The following guidelines must be followed to comply with the law:
Dunnage … loose packing material used to protect a ship's cargo from damage during transport … prohibited less than 25 miles from land.
Food waste, paper, rags, glass, metal, bottles and similar materials … prohibited less than 12 miles from land.
Ground food waste, paper, rags, etc., prohibited less than 3 miles from land.
If you spill any amount of hazardous waste or oil into the water, you must notify the US Coast Guard National Response Center at 1-800-424-8802, contact your local Coast Guard Station on Channels 9 or 16 or click here then mouse over contact us to e-mail the center (
lst-nrcinfo@comdt.uscg.mil). Failure to report a spill may result in a civil penalty and/or imprisonment.
If you are the type of boater who takes pride in your vessel and stays atop engine and boat maintenance you don't want your efforts overlooked because you neglected to remove grease and oil smudges, stains and spills from your engine, bilge and other areas of your boat.
Smart boaters know that a premium-grade, biodegradable de-greaser makes it easy to keep their boats sparkling and clean from engine to stern.
Most de-greasers remove oil and other petroleum-based agents. But marine de-greasers are made especially for boats and use near the water. The better products are all-purpose cleaners that can safely be used on boat engines, bilges and throughout the vessel
