Repair & maintenance guides
Plain-English, step by step, written for owners. Pick your engine to see the guides that apply to it.
376 of 509 guides · page 6 of 16

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.

How to Check and Change Coolant in a Closed Cooling System
Check, test and change the coolant in a freshwater-cooled (closed cooling) inboard, sterndrive or diesel, and learn the heat exchanger basics that keep it working. Old coolant quietly eats hoses, pumps and engine passages, and many boats go a decade without a change.

How to Check and Change Marine Transmission (Gearbox) Oil
Check, read and change the oil in the reverse gear behind your inboard diesel (ZF/Hurth, Kanzaki, Yanmar KM, Volvo Penta MS and similar). Learn what milky, burnt or gritty oil means, and why the oil cooler and its zinc matter.

How to Check and Test a Gasoline Vapor (Fume) Detector
A gasoline vapor detector sniffs the bilge all the time and sounds an alarm long before fumes can explode. Learn how these detectors work, where the sensor belongs, how to test the system the way its maker says, what causes false alarms, what to do when it goes off, and why it never replaces the blower and your own sniff test.

How to Check the Cutless Bearing, Prop Shaft and Strut
Find out if new vibration or rumbling from the stern is a worn cutless bearing, a bent shaft, a loose strut or poor engine alignment, using simple checks you can do at the dock and at haul-out. Catching bearing wear early protects the shaft, the seal and the transmission.

How to Check, Adjust and Repack a Stuffing Box (and Care for a Dripless Shaft Seal)
Learn the right drip rate for a traditional packing gland, how to adjust it safely, when to repack it, and how to inspect and service a dripless shaft seal. The shaft seal is one of the few holes in an inboard boat that moves, and a neglected one can sink a boat at the dock.

How to Check, Mount and Replace Boat Fire Extinguishers
A monthly five-minute check of every fire extinguisher aboard, plus how the 2022 Coast Guard rule changes affect you, where to mount them, and when to recharge or replace. A boat fire spreads in seconds, and an extinguisher with a dead gauge, missing pin or expired date will not help you or pass a boarding.

How to Choose and Fit Life Jackets for Children and Babies
Pick the right Coast Guard-approved life jacket for each child by weight, check the fit so it can't slip off, look for head support and a crotch strap on little ones, and learn the federal and state wear rules. Inflatables are not for kids, and a life jacket never replaces an adult watching.

How to Choose, Install and Adjust Trailer Guide-Ons (Posts or Bunks)
Add or tune the side guides on your boat trailer so the hull lines up in wind and current, the posts stay visible at the ramp and nothing rubs the gelcoat on the road. Covers post vs. bunk guide-ons, lighted posts, mounting height, side clearance and yearly care.

How to Choose, Install and Maintain an Onboard Battery Charger
Pick the right marine charger for your batteries (how many banks, how many amps, flooded, AGM or lithium), mount and fuse it safely, set the charge profile, and use it to keep batteries healthy all season and through the winter. The AC (shore power) side is a job for a marine electrician.

How to Clean and Care for a Boat Windshield (Acrylic, Polycarbonate or Glass)
Clean your windshield without scratching it, tell acrylic, polycarbonate and glass apart, deal with haze, crazing and small cracks, stop frame leaks, and keep wipers and the walk-through door working.

How to Clean and Care for Clear Vinyl (Isinglass) and Polycarbonate Enclosure Panels
Keep the clear windows in your dodger, bimini curtains or full enclosure clear for years by cleaning them the right way, storing them without scratches and avoiding the cold-weather and chemical mistakes that ruin them. Covers soft clear vinyl, coated vinyl like Strataglass, rigid panels and zippers.

How to Clean and Maintain Shower Sump and Macerator Pumps (and Stay Legal)
The shower sump pump fights hair and soap scum every day, and the macerator empties the holding tank, but only where that is legal. Learn how to clean the sump and filter, test the float switch, avoid burning out pumps by running them dry, follow the 3-mile and no-discharge rules, and winterize both.

How to Clean and Protect Boat Canvas, Bimini Tops and Vinyl Seats
Wash your bimini, covers and enclosure the right way, beat mildew without wrecking the stitching, keep vinyl seats soft and stain-free, look after zippers and snaps, and store everything so it comes out clean next spring.

How to Clean and Sanitize Your Boat's Freshwater Tank and Lines
Get rid of slime, stale taste and smells in your boat's drinking water system. Scrub the tank through the inspection port if you can, sanitize the tank and every line with the right dose of plain bleach, then flush until the water tastes clean again.

How to Clean the Raw-Water Strainer and Replace the Impeller on a Marine Diesel
Clean the sea strainer and swap the rubber impeller in the raw-water pump of a Yanmar, Volvo Penta, Westerbeke, Beta or similar inboard diesel. A worn impeller is one of the most common reasons a diesel overheats, and this job takes about an hour with basic tools.

How to Clean Your Boat's Bilge (Legally, and Without the Smell)
Get oil, sludge and debris out of the bilge without pumping pollution overboard, choose absorbents that actually work, track down bilge odors, clear limber holes and the pump pickup, and dispose of the mess the right way.

How to Clean, Protect and Inspect Stainless Steel Boat Hardware
Remove tea stains and rust from rails, cleats and fittings without scratching them, passivate stainless so it stays clean longer, understand why 304 and 316 behave differently, and spot the hidden crevice corrosion that weakens fittings from underneath.

How to Clean, Protect and Restore Non-Skid Decks
Get dirt, fish blood, rust and mildew out of textured non-skid without wearing it away, learn why ordinary wax makes it dangerously slick, and decide when worn non-skid needs a deck paint with grip additive or traction pads instead.

How to Clean, Remove Oxidation and Wax Your Boat's Gelcoat (Plus Pontoon Tubes)
Wash your hull the right way, bring back chalky, faded gelcoat with compound, and seal it with wax so it stays glossy and protected from the sun. Includes how to clean and protect the aluminum tubes on a pontoon boat.

How to Deep Clean a Boat Holding Tank
Clear the buildup that causes odors, slow pump-outs and false tank-level readings with a twice-a-year deep clean: pump out, rinse, soak with a tank-safe cleaning mix, slosh, pump out and rinse again, then inspect the tank and fittings while they are clean.

How to Detail Your Boat's Interior (Vinyl Seats, Carpet, Storage and Drains)
Give your cockpit and cabin a proper detail. Clean marine vinyl without stripping its UV protection, wash snap-in and glued-down carpet, clear out cup holders, storage boxes and their drains, beat mildew and pink stains, and know which household cleaners to keep off your boat.

How to Do a Compression Test on an Outboard, Sterndrive, Inboard or PWC
A compression test tells you whether the pistons, rings, valves and head gasket in each cylinder are sealing. Learn when to do one, how to do it safely, how to read the numbers by comparing cylinders, and what a wet test and a leak-down test add.

How to Dry or Replace Waterlogged Boat Seat Cushion Foam
Stop the soggy-seat problem: find out why the foam inside boat cushions holds water, dry it out the fast way, and choose the right replacement foam (standard, closed-cell or quick-drying reticulated) so your seats stay dry, firm and mildew-free.
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.