BoatMend

Repair & maintenance guides

Plain-English, step by step, written for owners. Pick your engine to see the guides that apply to it.

338 of 509 guides · page 9 of 15

Hull & systemsEasy

How to Replace Gas Struts on Boat Hatches, Seats and Consoles

Measure, buy and fit the right gas struts (lift supports) so hatches, seat lids and console doors stay open safely instead of dropping on your head or fingers.

45 min All engines Shop: $100-300
ElectricalModerate

How to Replace Marine Speakers (Including Tower Speakers)

Pick replacement speakers that fit the cutout, match your stereo or amplifier's power and impedance, survive sun and spray, and don't throw off your compass. Then wire them with the right polarity and seal them so water can't reach the back.

2 h All engines Shop: $150-400
Hull & systemsModerate

How to Replace or Re-Cover a Bimini Top

Decide whether you need new canvas or a whole new top, measure your frame the right way, pick a fabric that will last in the sun, check the frame and hardware, and swap the canvas yourself or brief a canvas shop.

3 h All engines Shop: $300-1500
Routine serviceAdvanced

How to Replace the Water Pump Impeller

Replace the rubber impeller that pumps cooling water through your engine, the part most often behind overheating. On many outboards it is a two-hour driveway job that saves a shop bill of several hundred dollars and prevents far costlier heat damage.

2 h 30 min Outboard, Sterndrive (I/O), Gas inboard Shop: $250-650
ElectricalModerate

How to Run New Wires Through a Boat (Chase Tubes, Pull Lines and Deck Penetrations)

Get a new transducer cable, light or power wire from the stern to the helm or up through the deck without a fight: use the chase tube and a fish tape or pull string, protect the wire from chafe and heat, support it every 18 inches, seal every penetration and label both ends.

3 h All engines Shop: $150-600
Routine serviceEasy

How to Sea Trial Your Boat After Maintenance or Repair

A step-by-step test run after service work: dock checks first (leaks, fluids, steering, kill switch), then a gradual climb through the RPM range while you watch temperature and pressure, a wide-open-throttle check against your engine's spec, shifting and trim tests, and a bilge check afterward. Catch a loose clamp or a missed step at the dock, not miles out.

1 h Outboard, Sterndrive (I/O), Gas inboard, Marine diesel, Jet ski / PWC
ElectricalModerate

How to Size a House Battery Bank: Load List, Usable Capacity and Charging

Work out how many amp-hours your boat really uses in a day, how much of a battery's rated capacity you can actually use with lead-acid, AGM or lithium, how much reserve to add, and how your charging sources change the answer, so you buy the right house bank the first time.

2 h All engines
Rules & seamanshipEasy

How to Size, Rig and Inspect Dock Lines and Fenders

Pick the right dock line diameter and fender size for your boat, set up bow, stern and spring lines in a slip, add chafe gear, inspect for wear and UV damage, and double everything up before a storm.

1 h All engines
Hull & systemsEasy

How to Test and Clean Your Bilge Pump and Float Switch

Make sure your bilge pump actually moves water overboard, both on the manual switch and automatically through the float switch. A working bilge pump is one of the most important safety systems on any boat that stays in the water.

45 min All engines Shop: $100-250
ElectricalEasy

How to Test and Fix Your Boat's Navigation Lights

Learn which navigation lights your boat must show and when, then test them and fix the usual culprits such as corroded sockets, loose pole-light plugs and blown bulbs. Working lights are legally required at night and in poor visibility and are how other boats see which way you are heading.

1 h All engines Shop: $100-300
Routine serviceModerate

How to Test and Replace the Engine Thermostat

Find, test and replace the thermostat that controls your engine's operating temperature. A stuck thermostat can make an engine overheat or run too cold. On most outboards and many sterndrives it is a one-hour job with basic tools.

1 h 15 min Outboard, Sterndrive (I/O), Gas inboard Shop: $150-400
Hull & systemsEasy

How to Touch Up Paint and Corrosion on an Outboard or Sterndrive

Bare aluminum on a lower unit or sterndrive corrodes fast, especially in salt water. Learn how to find the cause, clean off corrosion, prime and repaint with the right products, and what must never be painted, such as anodes and sensors.

2 h Outboard, Sterndrive (I/O) Shop: $150-500
ElectricalModerate

How to Troubleshoot Dash Gauges, a Dead Tachometer or a Wrong Fuel Gauge

Work through dead or wrong dash gauges from the cheapest check to the most involved: fuses and breakers, power and ground, the gauge-versus-sender test, the tachometer's pulse setting and the extra checks for digital network gauges. Most gauge problems turn out to be a bad connection, not a bad gauge.

1 h Outboard, Sterndrive (I/O), Gas inboard, Marine diesel Shop: $150-450
ElectricalModerate

How to Upgrade Your Boat's Lighting to LED (and Keep Your Nav Lights Legal)

Switch cabin, cockpit and courtesy lights to LED to cut battery drain and bulb changes, choose navigation lights that are actually USCG-certified (not just LED bulbs), check voltage range and dimmers, seal every connection, and run the Coast Guard's simple VHF test to make sure the new lights aren't deafening your radio or AIS.

3 h All engines Shop: $200-800
ElectricalModerate

How to Use a 1-2-Both Battery Switch and Run Two Batteries

Learn what the 1, 2, Both and Off positions really do, a simple routine that keeps one battery ready to start the engine, how to check that both batteries are charging, and when an automatic charging relay makes life easier. Rewiring high-current cables is a job for a marine electrician.

45 min Outboard, Sterndrive (I/O), Gas inboard, Marine diesel Shop: $250-800
Routine serviceEasy

How to Use an Oil Extractor Pump for Boat Oil Changes

Change engine oil cleanly through the dipstick tube with a manual or electric extractor: know which engines it suits, warm the oil first, get as much out as you can, then refill to the dipstick, recycle the old oil and clean the pump so it's ready next time.

1 h Sterndrive (I/O), Gas inboard, Marine diesel, Outboard Shop: $150-350
SeasonalModerate

How to Winterize an Outboard Engine

Protect your outboard from freeze damage, stale fuel and internal corrosion over the off-season. Most owners can do it in an afternoon with basic tools, compared with a shop bill that often runs several hundred dollars.

3 h Outboard Shop: $250-500
ElectricalModerate

How to Wire a 12, 24 or 36-Volt Trolling Motor and Charge Its Batteries

Set up the battery bank for your electric trolling motor the right way: matched deep-cycle batteries in series or parallel, a circuit breaker sized from the motor maker's chart, a proper plug, and a multi-bank charger that keeps every battery healthy. High-current wiring that runs long distances or ties into other systems is a job for a marine electrician.

2 h All engines Shop: $150-500
ElectricalModerate

How to Wire a Bilge Pump Correctly (Automatic Float, Panel Switch and Fuse)

Wire your bilge pump so the automatic float works even with the battery switch off, the helm switch gives you a manual override, and every circuit has the right fuse, wire size and connections kept above the bilge water. A pump that is wired wrong can leave the boat unprotected exactly when nobody is aboard.

2 h 30 min All engines Shop: $150-450
ElectricalModerate

How to Wire a Marine Stereo, Speakers and Amplifier Safely

Install or fix a boat stereo the way that keeps it working and keeps your battery alive: marine-rated gear, a fused feed from the panel, a solid ground, a plan for the always-on memory wire, UV-proof speakers, and an amplifier fused right at the battery. Plus how to stop the stereo from messing with your VHF and compass.

4 h All engines Shop: $200-800
TroubleshootingEasy

How Water Gets Into Boat Fuel (and How to Stop It)

Water in the fuel is one of the top causes of rough running and dead engines, and it almost always has an entry point you can find. Work from the jar test through the fill cap O-ring, a recessed deck fill, the tank vent, the sending unit gasket and your washdown habits, and learn how much condensation really matters.

1 h Outboard, Sterndrive (I/O), Gas inboard, Marine diesel Shop: $100-400
Hull & systemsModerate

Hull Blisters (Osmosis): How to Tell Cosmetic Pimples From Serious Pox

Learn what osmotic blisters are, how to inspect a fiberglass bottom at haul-out, which blisters you can fix yourself with epoxy, what moisture meter readings can and can't tell you, and when to hire an independent surveyor.

4 h All engines Shop: $400-2000
Hull & systemsModerate

Hull Potential Survey: Checking Corrosion Protection with a Reference Electrode

A silver/silver-chloride reference electrode and an ordinary multimeter show whether your underwater metals are really protected by their anodes, whether every fitting is bonded, and whether shore power or the slip is upsetting things. Learn how to take the readings, what under- and over-protection mean in plain terms, and when to call a marine electrician or corrosion specialist.

1 h Gas inboard, Sterndrive (I/O), Outboard, Marine diesel Shop: $150-500
Hull & systemsModerate

Hydraulic Steering: Check Fluid, Bleed Air and Fix Stiff or Loose Steering

Check the fluid in your hydraulic steering helm, bleed out the air that makes steering spongy, and track down the usual causes of stiff, loose or noisy steering. Includes notes for boats with mechanical cable steering.

1 h 30 min Outboard, Sterndrive (I/O), Gas inboard Shop: $150-400

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.