20 Must-Have Engine Maintenance Products

By Chris Caswell

Your power plant is a complex piece of machinery, and it requires a wide range of products to keep it running and looking good. Poke through any skipper’s dock box or those garage shelves set aside for boat gear, and you’re likely to find a witch’s brew of liquids, sprays, and mystery potions that promise more power, lowered fuel consumption, fewer breakdowns, easier maintenance, and reduced hair loss. Oops, that’s my dock box.

To test and compare all of the products available would keep a laboratory busy for years, but I’ve found a faster way: just ask around. Starting with my own dock box, I asked a bunch of boat owners what products they found particularly useful in maintaining their boats. They, of course, relied on the empirical method of testing: if a product works, they continued using it. If it didn’t, they tossed it.

So here’s a list of 20 engine maintenance products that have survived the brutal march-or-die testing of experienced boat owners. You’ll find these items at your local marine hardware store.

1. WD-40: This was mentioned by nearly every boater, and it’s used for everything from protecting metal parts from corrosion to freeing up jammed padlocks. The distinctive blue-and-yellow spray cans are a first line of attack for most metal problems.
2. Corrosion Block: Brought to boating from aerospace, this spray kills corrosion on contact. Intended to protect metal surfaces, it acts as both a lubricant and as a penetrant to loosen seized parts. Of particular value is its ability to protect and even restore electronic and electrical systems from water damage.
3. Engine Degreaser: I’ve used Gunk for decades on both boats and cars, but many report success with Permatex Enviro-Safe with citrus solvents that are biodegradable. Before pumping your bilge, however, remember that the grease isn’t biodegradable.
4. Liquid Electrical Tape: Use this Star brite liquid to protect wiring connections, soldered joints, and any place where corrosion can attack your wires. It applies easily, dries quickly, and leaves a watertight covering far superior to the usual wrapping of electrical tape.
5. Thread Locker: Boats vibrate and fastenings will loosen unless you use Loctite to seal the threads. As good as an aircraft-style lock nut, a drop of Loctite lasts forever, holds securely, but can be easily broken loose when you need to remove a nut.
6. Three-In-One Oil: Though a rather archaic type of lubricating oil (it’s what your father probably used when sharpening his axe), this showed up in a surprising number of dock boxes. It makes drilling through metal easier, and it can be used to saturate a frozen fitting.
7. Armor-All: Originally made to seal tire sidewalls against cracking, Armor-All now comes in a variety of use-specific products, but I like the original for keeping rubber gaskets, hoses and drive belts in like-new condition.
8. Fuel Antibiotics: Whether you use gas or diesel, your fuel tank is a spawning ground for bacteria, algae and fungus that can clog your filters and stall your engine. Available from several companies such as Bioguard, Biobor and Star brite, a fuel biocide is a shot of penicillin for your fuel.
9. Gasket Sealant: Squeezed from a tube like toothpaste, these gooey materials form a one-piece gasket that resists cracking and shrinking and will usually last far longer than conventional cork or composite gaskets. Use this stuff on valve covers, oil pans, timing covers, water pumps and just about any metal surface-to-surface joint. Several companies–Permatex, Loctite, Star brite and BoatLIFE–offer liquid gaskets for different heat ranges and uses.
10. Carburetor Cleaner: Spray this potion into your carb, and it will dissolve and remove the gum and varnish that is reducing your engine efficiency. Chokes, heat control valves and fuel injectors can also benefit from a squirt. From CRC and Valvtect.
11. Marvel Mystery Oil: Sounds like something a snake-oil salesman would love, but those who use it swear by it. A fuel and oil additive, it is said to lubricate the engine, reduce wear, and increase mileage. It sounds like something from the ‘30s (it is), and mechanics have used it for decades.
12. Lead Substitute: Older marine engines will suffer accelerated wear of the valve seats when using unleaded gasoline, and Protective Lead Substitute from Valvtect is a low concentration additive that lubricates the valve area without metallic lead.
13. Water Absorber: Leave your fuel tank half or less full, and you’re likely to have condensation inside the tank that not only causes your engine to run rough, but can also corrode the fuel system and your tank. This fuel additive from Star brite, available for gas or diesel, emulsifies the water so it can burn through your engine safely.
14. Naval Jelly: Sounds like a Saturday Night Live joke, right? This stuff has been around for decades, and the jelly like substance can be smeared onto anything that has a coating of rust. Leave it for a while, rinse it off, and the rust is history. Great stuff when you need to free up those rusty bolts.
15. Fogging Oil: This is an absolute necessity when putting your engine to bed for the winter. Spray some Star brite Fogging Oil into the air intake while the engine is running to coat the innards and, after the engine stops, squirt some more into each spark plug hole. It will prevent corrosion over the winter, and it doesn’t inhibit the engine from starting quickly in the spring.
16. Starting Fluid: There are a host of manufacturers for starting fluid, which you spray into the carb (and sometimes into the cylinders directly) to get that recalcitrant engine to fire. Be wary, because these fumes are not only explosive but heavier than air, so ventilate your engine compartment.
17. Fuel Stabilizer: From several companies (I like Star brite EZ-To-Store EZ-To-Start), this additive protects your fuel during long storage. Fuel can turn to gum, resin and varnish surprisingly quickly, and this treatment allows you to leave fuel in the tank and use it next season without problems.
18. Winterizing Antifreeze: Far more powerful than the normal antifreeze in your cooling system, this solution can protect your engine from damage caused by the expansion of water as it freezes. Star brite offers two non-toxic winter antifreeze products, for either -50°F or -100°F protection. Brrr.
19. Water Probe Indicator: Want to know if you have water in your gas or diesel tank? Apply a little of this liquid to a dipstick, insert it into the fuel tank and, in minutes, a color change will indicate the presence of water. From MDR.

20. Gloves In A Bottle: This stuff won’t protect your engine, but it will protect your hands while working on the engine. It goes on like a hand lotion and forms an invisible protection that prevents odors, stains or paint from penetrating your skin. Oil, tar, paint–everything rinses off easily when you wash your hands later. You’ll be much more presentable at the dinner table.