MerCruiser Maintenance FAQs

How can I find my closest authorized MerCruiser dealer?

Authorized MerCruiser dealers in the United States and Canada can be found under Find a Dealer on this website.

Links to regions outside of the United States and Canada can be found on the Contact Us page.

How often should spark plugs be changed?

Every 300 hours or 3 years, whichever comes first.

How often should coolant be changed on engines with closed cooling?

Every 5 years.

For optimum performance and maximum protection use Mercury /Quicksilver Extended Life Coolant / Antifreeze.

How often should my seawater pump impeller be serviced?

Every 300 hours or 3 years, whichever comes first.

Is it better to change my engine oil/gear lube at the beginning or end of the season?

It is better to change the oil and gear lube at the end of the season, prior to storage. Lubricants naturally accumulate moisture, combustion by-products, and other contaminants during use. It can be detrimental to store an engine or drive with large amounts of these contaminants present.

Where can I get factory Service manuals, Parts manuals, or Operation, Maintenance & Warranty manuals?

You can order all available literature online. You could also order all literature through any authorized Mercury dealer. Please have your outboard or sterndrive serial number before placing the order.

Where do I find maintenance and lubrication information for my engine?

The Operation, Maintenance & Warranty manual outlines the typical maintenance and lubrication items. If your manual is missing or damaged, please order online or through any authorized Mercury dealer. Please have your outboard or sterndrive serial number before placing the order.

How often should maintenance be performed?

Maintenance intervals vary depending on the specific engine and drive model. Recommended maintenance intervals are included in your Operation, Maintenance & Warranty manual or service manual.

How often should I change my sacrificial anodes?

Because they are self-sacrificing, the anodes must be inspected often and replaced when 50% consumed. Anodes may also become coated (calcified) with a white chalky coating or marine growth. Either of these will prevent the anode from sacrificing itself and, therefore, prevent it from protecting your drive and other underwater components. Use sandpaper to remove any coating. DO NOT use a wire brush.

Should I use Premium Blend or High Performance gear lube in my sterndrive?

Mercury High Performance gear lube is recommended for use in all sterndrives.

My Operation, Maintenance & Warranty manual lists the oil capacity for my engine, but when I change the oil it won't take that much without being overfilled. Why?

The engine oil capacities given in the Operation, Maintenance & Warranty and Service manuals are approximate and indicate what the capacity of the entire lubrication system is. A small amount of oil remains in the crankcase, oil lines, etc. This is why it is difficult to get the indicated amount of oil in the engine without it being overfilled. You should always fill the crankcase according to the dipstick when the engine is level, preferably with the boat at rest in the water. If the oil is at the full mark on the dipstick, then it is at the proper level regardless of how much you put in. It is important not to overfill or under fill the crankcase. The engine oil level should always be between the add and the full marks on the dipstick.

What type of fluid should I use in my power trim system?

Mercury/Quicksilver Power Trim and Steering Fluid – part # 92-858074K01

How often should I flush my engine in saltwater use?

For maximum corrosion protection, we recommend that the engine be flushed with freshwater after each saltwater use.

Do you have a freshwater flush kit to flush the engine while the boat is in the water?

Currently we offer flush kits for all 1988 and newer MerCruiser engine applications. And, we now offer kits that can be used with Bravo sterndrive, inboard, and towsport engines when the boat is in or out of the water. The flush attachment kit for Alpha engines can only be used when the boat is out of the water.

In all applications, the engine must be running when using a flush kit. See your MerCruiser dealer for details on the appropriate kit and additional components that will fit your engine and best suit your needs.

Why do I have to periodically check my engine alignment and lubricate the engine coupler?

With time and usage, the engine will sometimes get out of alignment with the transom assembly and sterndrive. For longest engine coupler life, it is important that the engine alignment be as accurate as possible. We recommend using Quicksilver Engine Coupler Spline Grease for proper lubrication. Damage caused by improper engine alignment or lack of lubrication is not covered under the limited warranty.

Do you have any tips for do-it-yourself maintenance?

If you are a person who likes to do-it-yourself, here are some suggestions for you:

  • Your MerCruiser power package is an advanced technological piece of machinery. Electronic ignition and special fuel delivery systems provide greater fuel economies, but are also more complex for the untrained technician.
  • Do not attempt any maintenance or repairs which are not covered in the service manual unless you are aware of the precautions and procedures required. Your safety is very important to us.
  • The service manual is written for the trained technician. Do not attempt repairs if you do not understand the procedures.  
  • There are special tools and equipment that are required to perform some repairs. Do not attempt these repairs unless you have these special tools and/or equipment.
  • Please do not contact the dealer, customer service office, or the factory to request troubleshooting help or to request the repair procedure. It is difficult to diagnose a problem over the telephone.

Remember, your authorized dealer is there to provide service for your power package. Dealers have qualified, factory-trained technicians.

What kind of spare parts should I carry on my boat for my MerCruiser?

Some suggested items would include a floating prop wrench, a spare prop and attaching hardware, spark plugs, belt(s), oil, power trim and steering fluid, High Performance gear lube, water separating fuel filter, and appropriate fuses.

How can I obtain parts or service for my Quicksilver generator?

You can contact the Generac Corporation for this information at 1-800-333-1322.