Repair & maintenance guides

Holding Tank Level Monitors: Fix, Calibrate or Upgrade Your Tank Gauge

Find out why your holding tank gauge reads wrong, clean or calibrate the sensor, and choose a better internal or external monitor so you never overfill the tank and push sewage up the vent.

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 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 Bleed Air From a Marine Diesel Fuel System

A diesel that sucks air after a filter change, a fuel leak or running the tank dry may not start until the air is pushed out. Learn the order that works on most older mechanical diesels, why common-rail engines are different, how to protect the starter and exhaust while cranking, and the high-pressure fuel dangers you must respect.

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 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 Holding Tank Vent and Replace the Vent Filter

A blocked holding tank vent makes the head gurgle, pressurizes the tank every flush and can collapse it at the pump-out dock. Learn the warning signs, how to clear the vent fitting and hose, when and how to replace the carbon vent filter, and how to keep insects and overfills from plugging it again.

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.

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 and Top Up Power Trim and Tilt Fluid

Check and top up the hydraulic fluid in your power trim and tilt unit, then work through the simple checks when the motor won't go up, won't go down or slowly sinks. Most trim problems are a dead battery, a bad relay, low fluid or a release valve left open, and you can find those yourself.

How to Check for Worn Outboard Motor Mounts

A clunk when you shift, buzzing vibration at idle or a motor that wobbles side to side can mean the rubber mounts between the outboard and its bracket are worn out. Learn how to rule out the cheap causes first, check the mounts yourself and know when replacement belongs in a shop.

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.