Midseason Tune-up

10 quick steps to keep your boat tiptop.

July 6, 2010

Boats are like trophy wives: The maintenance never ends. Staying on top of it is time well spent, ensuring more pleasurable hours afloat. Here are 10 items you should check midway through the season, or better yet, on a regular basis.

Pore over your boat, tightening every fastener with the appropriate tool. Common “offenders” include windshield fasteners, bow rails and the screws securing seats to the cockpit sole. Engine-mounted accessories — alternator, filter brackets, etc. — are not immune from being loosey-goosey either.

Regularly open and close seacocks to make sure they work. If the handle doesn’t operate smoothly, haul the boat and either dismantle and rebuild, or replace, the valve. If you see a single clamp, as shown, add another for safety.


Pop the caps off flooded cell batteries and check the electrolyte levels. Use distilled water to top off low cells. Tap water contains minerals that can shorten battery life.

Your sacrificial anodes — many are aluminum — thwart stray current and galvanic corrosion from attacking the metal parts of your boat, such as through-hull fittings, shafts and rudders, by corroding before the metals they’re intended to protect. If a zinc has lost more than half its size, it’s time to replace it. Replace only with anodes certified Military Specification A18001K. Cheap anodes don’t slough off oxides that keep zincs working to the max.

As a general rule, belts should not deflect more than onequarter inch when you press on them between pulleys. If you find a loose one, it may mean a worn belt or a loose pulley. Check it out before you end up calling a tow boat. Keep a universal “no-tools” replacement belt stowed aboard.


Transmissions, trim tabs, steering, cooling — many systems require the proper amount of good, clean fluid. For coolant, check the overflow bottle every time you pop the hatch. Compare the level against the marked “cold fill” line. Use the appropriate fluid for steering and trim tabs, being careful no debris enters a hydraulic system.

Throttle and shift linkages, steering systems, trim rams and shift rods require greasing to work smoothly and stave off (the eventual) corrosion. Smear dabs on linkages with your fingers. Locate the engine zerk fittings, hitting each with a grease gun.

Engine Oil
Check levels every time you start up, but at about 100 hours it’s wise to remove all the old oil, hauling out the btandodat and draining it from the pan. Or, as a second choice, use a pump that sucks the oil through the dipstick tube. And don’t forget outboard and stern-drive gear case lube.


Change the oil filter as well as checking and replacing the fuel filters if they’re clogged.

Dinged Wheel
Even a small ding can damage your engine and drivetrain by creating vibration. You can carve a valley with a tack hammer if you hit the mountain enough times. Have the wheel reconditioned and run your spare. You do have a spare, right? Complete with all the hardware needed to install?

And don’t forget…
[1] Check out your fuel filter. A remote water-separating fuel filter, like the easily installed inspection bowl models from Racor, makes it easy to see if there’s water or contaminants in your fuel system.


[2] While you’re at the batteries, swap out those wing nuts for locknuts, those with the nylon insert, and torque the terminal connections tight so they won’t come loose when you least want them to. Tight terminals ensure best charging.

[3] Bungs are cone-shaped chunks of wood that you can jam into the pipe portion of a seacock should the hose or valve fail. They can be purchased, or you can fashion them from softwood such as pine or cedar, which swells tight once wet. Hardwood bungs are ill-advised, since these can split fittings.

[4] Fuel fills, hatches and deck plates all have O-rings that create a watertight seal. Order replacements for any that are abraded, worn or loose.

Service Providers: Prop Reconditioners
H&H Propeller,
Michigan Wheel Corp.,
Delta Propeller,


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