Posted by Lighthouse Marine Supply on Sep 19th 2025
Off-Season Essentials: 5 Steps to Extend Your Marine Engine’s Life
A little off-season care prevents spring surprises. Focus on these five areas before storage:
Oil Change
Why: Used oil holds acids and moisture that corrode internals.
Do: Warm engine, drain oil, replace filter, refill with correct marine-grade oil. Run briefly and check for leaks.
Don’t forget: Change gear lube on sterndrives/outboards; milky lube = water intrusion.
Exhaust & Cooling System Flush
Why: Salt and silt cause corrosion and blockages; trapped water can freeze.
Do: Freshwater flush to temp. For raw-water systems, circulate non-toxic marine antifreeze until colored fluid exits exhaust. Check closed-cooling strength and heat exchanger zincs.
Fuel Stabilization
Why: Ethanol fuel absorbs moisture and degrades, gumming injectors/carburetors.
Do: Add marine stabilizer, fill tank to ~95%, run 10–15 minutes to pull treated fuel through. Replace water-separating fuel filter.
Spark Plugs & Ignition
Why: Weak ignition = hard starts and misfires in spring.
Do: Replace plugs to spec and gap correctly. Inspect wires, coils, and (if equipped) distributor cap/rotor. A dab of dielectric grease on boots helps keep moisture out.
Anode Replacement
Why: Sacrificial anodes protect underwater metals from galvanic corrosion.
Do: Replace if 50%+ consumed or cracked. Match water type—zinc (salt), aluminum (salt/brackish), magnesium (fresh). Ensure bare-metal contact; never paint anodes.
Quick Extras
Call 631-722-5700 or email sales@marineengineparts.com. We stock OEM and premium options for MerCruiser, Volvo Penta, Crusader, Yamaha, Mercury/Mariner, Evinrude/Johnson, Yanmar, Cummins, and Caterpillar.
Oil Change
Why: Used oil holds acids and moisture that corrode internals.
Do: Warm engine, drain oil, replace filter, refill with correct marine-grade oil. Run briefly and check for leaks.
Don’t forget: Change gear lube on sterndrives/outboards; milky lube = water intrusion.
Exhaust & Cooling System Flush
Why: Salt and silt cause corrosion and blockages; trapped water can freeze.
Do: Freshwater flush to temp. For raw-water systems, circulate non-toxic marine antifreeze until colored fluid exits exhaust. Check closed-cooling strength and heat exchanger zincs.
Fuel Stabilization
Why: Ethanol fuel absorbs moisture and degrades, gumming injectors/carburetors.
Do: Add marine stabilizer, fill tank to ~95%, run 10–15 minutes to pull treated fuel through. Replace water-separating fuel filter.
Spark Plugs & Ignition
Why: Weak ignition = hard starts and misfires in spring.
Do: Replace plugs to spec and gap correctly. Inspect wires, coils, and (if equipped) distributor cap/rotor. A dab of dielectric grease on boots helps keep moisture out.
Anode Replacement
Why: Sacrificial anodes protect underwater metals from galvanic corrosion.
Do: Replace if 50%+ consumed or cracked. Match water type—zinc (salt), aluminum (salt/brackish), magnesium (fresh). Ensure bare-metal contact; never paint anodes.
Quick Extras
- Battery on a smart maintainer, clean terminals.
- Inspect belts, hoses, clamps; fix small issues now.
- Light corrosion inhibitor on electrical connections.
Call 631-722-5700 or email sales@marineengineparts.com. We stock OEM and premium options for MerCruiser, Volvo Penta, Crusader, Yamaha, Mercury/Mariner, Evinrude/Johnson, Yanmar, Cummins, and Caterpillar.