Repair & maintenance guides
Plain-English, step by step, written for owners. Pick your engine to see the guides that apply to it.
377 of 509 guides · page 5 of 16

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.

Hiring a Delivery Captain: Moving Your Boat by Water vs by Truck, Vetting, Contract, Costs and Owner Prep
Decide whether to move a boat on its own bottom with a hired delivery captain or on a truck, then vet the captain (Coast Guard credential, experience, references, insurance), put the job in a written contract, budget the day rate and expenses, and get the boat, paperwork and insurance ready before the lines come off.

Hiring a Diver for In-Water Hull Cleaning: How Often, What It Does to Your Paint, and What to Ask
If your boat lives in the water, a hull-cleaning diver keeps growth off the bottom, prop and through-hulls between haul-outs. Learn how often to schedule cleanings, why scrubbing wears away ablative paint, the local rules some harbors (like San Diego and Marina del Rey) put on in-water cleaning, and what a good diver report should tell you about zincs, the prop and the paint.

Hose Clamps on Boats: Choosing, Installing and Inspecting Them
A rusted or wrong hose clamp can sink a boat at the dock, leak fuel or let exhaust into the cabin. Learn which clamps belong on a boat (all-316 stainless, embossed band, T-bolt where needed), when to double them, how tight is tight enough, and how to find the ones that are about to fail.

How Much Does Your Outboard Really Charge? Rated vs Net Output, Rpm and Extra Batteries
The amp rating on an outboard's spec sheet is the most it can make at high rpm, not what reaches your battery at idle or trolling speed. Learn how outboard charging really works, how to find and measure your engine's output, how extra batteries and lithium change the picture, and how to plan your electrical use so you never come home with a dead battery.

How Much Is a Used Boat Worth? Pricing Guides, Comps and Condition
Work out a realistic price for a used boat, whether you're buying or selling: check sold and listed comps, read J.D. Power, BUCValu and ABOS values the right way, value the engines separately, adjust for hours, condition, upgrades and location, and know when a valuation survey is worth paying for.

How to Add and Read an Outboard Water Pressure Gauge
A water pressure gauge shows how hard your outboard's water pump is working, so you can spot a tired impeller or a clogged intake long before the overheat alarm sounds. Learn why it's worth having, how readings change with RPM and brand, how a gauge is plumbed in, and what to do when the number drops.

How to Add or Replace a Swim Platform on Your Boat
A swim platform makes swimming, fishing and climbing back aboard far easier, but it hangs off the most heavily loaded part of the hull, right next to the propeller and the exhaust. Learn the bolt-on options, how to check the transom and engine clearance, how to through-bolt with real backing plates, and the propeller and carbon monoxide rules that come with it.

How to Add or Upgrade Boat Cleats (Sizing, Placement and Backing Plates)
Most cleats that fail don't break; they pull out of the deck. Learn how to size a cleat to your dock lines, where to put new cleats for docking and spring lines, how to through-bolt them with real backing plates, how to protect a cored deck, and what's different about pop-up and pull-up cleats.

How to Adjust and Replace Trailer Bunks and Rollers So Your Boat Sits Right
Set up your boat trailer so the hull is supported in the right places: bunks and rollers clear of the strakes, the transom fully supported, the bow snug against the winch stop and the weight balanced on the tongue. Also covers replacing rotten bunk boards and worn carpet or rollers.

How to Break In a New or Rebuilt Boat Engine
The first hours on a new or rebuilt engine decide how well its piston rings seat and how long it lasts. Learn how to follow your maker's hour and RPM schedule, why you should keep changing the throttle, what to avoid (constant RPM, early full throttle, long idling), what to check every trip and when to do the first oil change.

How to Build a Damage-Control Kit: Plugs, Patches and a Plan for Leaks
Put together a labeled kit that can slow or stop water coming into your boat - softwood plugs tied at every through-hull, rescue tape, spare clamps, rubber and plywood patches, plastic sheeting, underwater sealant, a manual pump and the tools to reach a hidden leak - and practice with it so your crew knows where everything is.

How to Care for a Hydraulic Jack Plate (Fluid, Pump, Leaks, Grease and Height)
Keep a hydraulic jack plate (Bob's Machine Shop, T-H Marine Atlas, CMC, SeaStar style) lifting smoothly: check and top up the right fluid, keep the pump and relays dry, find leaks and slow drift, lubricate only the way your model calls for, set running height safely and prepare it for winter. Mounting and setback changes are dealer work.

How to Care for Boat Solar Panels, Connectors and the Charge Controller
A boat solar setup is quiet and almost maintenance-free, but salt, shade, loose connectors and a wrong battery setting quietly cut its output or hurt the batteries. Learn the cleaning, inspection and controller checks to do each season, and how to leave the system for winter.

How to Care for Your Anchor Locker and Keep the Chain Running Free
Empty, clean and drain the anchor locker, untwist and restow the rode so it runs out without jamming, tie the bitter end so it can be cut free in an emergency, and decide whether you really need a swivel. A tidy locker keeps the anchor ready when you need it fast.

How to Change Lower Unit (Gearcase) and Sterndrive Oil
Drain and refill the gear oil in your outboard lower unit or sterndrive, and learn to spot water intrusion before it destroys the gears. It is a 30-minute job that protects a gearcase costing thousands to replace.

How to Change the Oil and Filter on a 4-Stroke Outboard
Drain the old oil, swap the filter and refill with the right marine oil on your 4-stroke outboard. It is the most common service job, takes about an hour, and costs a fraction of the dealer price.

How to Check a Boat for Transom and Stringer Rot
Many older fiberglass boats have wood inside the transom, stringers and deck, and water that gets in slowly rots it. Learn the tap test, the flex test, how to read a moisture meter and the other warning signs, and why a rotten transom or stringer is a structural job for a pro, not a weekend patch.

How to Check and Adjust Boat Shift and Throttle Cables
Hard shifting, a lever that will not go fully into gear, or a gear that lands in a different spot every time usually point to the control cables. Learn how to find out whether the problem is the cable, the control box or the engine, how to adjust the cable ends, and when it is time to replace both cables.

How to Check and Care for Boat Trailer Surge Brakes
Understand how the hydraulic surge brakes on your boat trailer work, check the fluid, use the reverse lockout correctly and rinse salt out of them after every dunk. Simple habits that keep the brakes from seizing, dragging or failing when you need them.
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.