Repair & maintenance guides
Plain-English, step by step, written for owners. Pick your engine to see the guides that apply to it.
339 of 509 guides · page 4 of 15

Engine Warning Horn and Dash Lights: What They Usually Mean and What to Do
Learn what a warning horn, beeps or a dash light usually mean on a boat engine, from overheating and low oil pressure to water in the fuel and reduced-power (limp) mode. Find out what to do right away and when to stop the engine. Patterns differ by brand, so match what you hear and see to your owner's manual.

Engine Won't Start or Won't Crank - Troubleshooting Guide
Find out why your boat engine will not turn over or will not fire, starting with the simple things owners miss most, like the kill switch lanyard and battery switch. Many no-starts are fixed at the ramp in minutes without a tow.

EPIRB and PLB Care: Registration, Batteries, Self-Test and Mounting
Keep your 406 MHz emergency beacon ready to work on the worst day of your life. Register it free with NOAA and renew every two years, track the battery and hydrostatic release dates, run the self-test without triggering a false alert, and know what happens after you press the button.

Epoxy and Two-Part Paint Safety: How to Avoid Becoming Allergic
Epoxy and isocyanate-cured paints can make you allergic for life, sometimes after many jobs with no problem at all. Learn how sensitization happens, which gloves and clothing to wear, how to get epoxy off skin without solvents, when you need a respirator, and how to handle sanding dust and leftovers safely.

Ethanol (E10) Fuel Care: Stabilizer, Phase Separation, Fuel Lines and Tank Vents
Keep E10 gasoline from damaging your boat engine. Learn how to use stabilizer, test for water and phase separation, and inspect the fuel lines, primer bulb, anti-siphon valve and tank vent. Most fuel-related breakdowns start with one of these.

Extended Warranties and Service Plans for Boat Engines: Factory Plans vs Third-Party Contracts
Decide whether an extended service plan is worth it: how factory plans such as Mercury Product Protection and Yamaha Y.E.S. differ from third-party contracts, what they usually cover and exclude, why maintenance records decide claims, how deductibles, transfers and cancellations work, and the questions to ask before you sign. Practical guidance, not legal or financial advice.

FCC Ship Station License vs. a Free MMSI: Which One Your Boat Needs, and How to Keep It Current
Most U.S. recreational boats that stay in U.S. waters don't need an FCC radio license, but every DSC radio and AIS needs a registered MMSI. Learn when an FCC ship station license and operator permit are required (foreign ports, SSB/HF, satellite), how to get an MMSI from BoatUS, America's Boating Club or Shine Micro, and what to do when you sell, buy or rename a boat.

Financing a Boat: Loan Terms, Survey and Insurance Requirements, Liens and the True Cost of Ownership
Understand a boat loan before you sign: typical terms and down payments, what lenders check, why they want a survey and insurance, how the lien is recorded (Coast Guard preferred mortgage for documented boats, state title for the rest), how the payoff works when you sell, and how to add up the real yearly cost beyond the monthly payment. Practical guidance, not financial advice.

Fish Finder and Depth Sounder Transducers: Mounting, Fixing Bad Readings and Cleaning
Where and how to mount a transom-mount transducer so it reads cleanly at speed, how to track down lost bottom readings and noisy screens, how to clean and paint a transducer without ruining it, and why thru-hull transducers are a haul-out job for a pro.

Fish Finder Settings: How to Tune Your Sonar for a Clearer Picture
Get more out of your fish finder by setting frequency, gain (sensitivity), range, contrast, color palette and noise filters on purpose instead of leaving everything on auto, plus how to set the depth offset and track down interference from other electronics.

Fuel Anti-Siphon Valve: Diagnosing a Sticking Valve and Replacing It Safely
The anti-siphon valve at your built-in fuel tank stops gasoline from draining into the bilge if a fuel line breaks, but a cheap or sticky one can starve the engine at speed. Learn how to tell a restricted valve from a blocked vent or filter, how to clean or replace it with a quality valve of the right type, and why you should never pull the check ball out.

Fuel Demand Valves: Troubleshooting the Valve That Holds Back a Sealed Tank
Modern EPA-compliant fuel tanks stay sealed and build pressure in the sun, and a fuel demand valve keeps that pressure from pushing gasoline into the engine when it's off. Learn how it differs from an old-style ball anti-siphon valve, the symptoms of one that sticks closed or leaks through, how to rule out cheaper causes first, and why the replacement must be the same type, never a ball valve.

Fuel Gauge Reads Wrong or Empty? How to Test the Gauge, Sender and Wiring
Find out why your boat's fuel gauge reads empty, full, backward or jumps around, working from the free checks at the dash to testing the tank sender and replacing it safely. Most problems are a stuck float, a bad ground or a sender that doesn't match the gauge.

Fuel Pump Checks - Is It the Pump or Something Starving It?
Bogging at speed, surging or dying after a few minutes is often blamed on the fuel pump, but vents, filters, primer bulbs and anti-siphon valves cause the same symptoms. Learn how mechanical, pulse and electric pumps work, the safe checks you can do, what the primer bulb is telling you, and why a real pressure test needs the right gauge and the factory spec.

Fuel Smell on Board: What to Do and How to Find the Source
A gasoline smell on a boat is a fire and explosion warning. Learn what to do in the first minutes, the most common sources (fill and vent hoses, tank fittings, fuel lines, carburetors and injectors, overfilling), how to look safely, and when to stop and call a pro.

Fuse Keeps Blowing? How to Troubleshoot a Boat Fuse Block or Breaker Panel
Work through a blown fuse or tripping breaker the safe way: confirm it, tell a short from an overload, isolate the device or wire at fault, replace a worn breaker or panel switch with the same rating, and label every circuit, without ever fitting a bigger fuse.

Galvanic Isolator: Why Shore-Powered Boats Need One and How to Tell If It's Working
A galvanic isolator (or an isolation transformer on bigger boats) keeps stray DC current from the marina's ground wire from eating your anodes, drive and running gear, without cutting the safety ground. Learn what it does, the owner-level checks you can do, what failure looks like, and why the actual meter test is usually a job for a marine electrician.

Generator Pre-Trip Check: What to Inspect and Test Before a Cruise
A marine generator that quits on the first hot night of a cruise usually gave warning signs at the dock. Use this pre-departure checklist, based on generator makers' own advice, to inspect the oil, coolant, belt, raw-water side, exhaust and CO alarms, run the set under real load, and pack the right spares.

Get Your Boat Ready for the Road: Pre-Trailering Checklist
Most trailering trouble starts in the driveway: an engine left without support, a loose strap, a cover that balloons at 60 mph, gear that blows out or tongue weight that makes the rig sway. Work through this checklist before every trip and do a quick walkaround at each stop.

Guardian, Limp Home and Reduced Power Modes: Why Your Engine Cut Power and What to Do
Modern outboards and inboards cut power on their own when a sensor reports trouble. Learn what usually triggers Mercury's Engine Guardian, Yamaha's RPM reduction and other brands' limp-home modes, how to read the warning, and how to decide between idling home and stopping to call for help.

Gyro Stabilizer Care: Owner Checks for Seakeeper and Other Boat Gyros
A gyro stabilizer needs little from you, but what it needs matters. Learn how to start and shut it down correctly, keep its seawater cooling and zinc in shape, rinse it, read its hours and alarms, winterize it, and know which jobs belong to a certified dealer.

Harmful Algae Blooms: How Boaters Spot Them, Check Advisories and Clean Up Afterward
Blue-green algae and red tide can sicken people and kill dogs within hours. Learn what a bloom looks like, where to check state advisories before you launch, how to run the boat around one, and how to rinse the hull, trailer, gear and your dog afterward. Includes what health agencies say about eating fish from bloom areas.

Heat Exhaustion and Heat Stroke on a Boat: Prevention, Warning Signs and What to Do
Sun, reflected glare, little shade and too little water make boats a classic place for heat illness. Learn how to prevent it, how to tell heat exhaustion from heat stroke, how to cool someone down aboard, how to protect kids and pets, and when to call 911 or the Coast Guard. General first-aid information only, not medical advice.

Helping Another Boater: Your Duty to Assist, Safe Approaches, and When Not to Tow
What the law expects when you come across a boater in trouble, how to approach a disabled or sinking boat safely, how to take people aboard, the basics of a short tow, and when to stand by and call the Coast Guard, Sea Tow or TowBoatUS instead. People first, boats second.
Safety: BoatMend is for information only and does not replace a certified marine technician. You are responsible for your safety and your boat. Read the full disclaimer.