Mercury Mercruiser External Engine

Mercury MerCruiser External Outboard Parts - Resources and Information

Your MerCruiser external engine systems are just as important as what’s going on in your internal engine components. If these MerCruiser external systems fail, you can expect reduced performance, mechanical issues, and even complete engine failure. Therefore, protecting and keeping it in working order is absolutely essential for the best performance and safest experience out on the water. 

PartsVu offers Mercury MerCruiser equipped boats with all of the external engine system parts MerCruiser boaters need to perform their own repairs. And to help you find the right exhaust system parts plus in-depth articles for reference, check out some of our helpful MerCruiser resources:

• MerCruiser Inboard Maintenance
• MerCruiser Maintenance Parts Library
• Mercury Outboard and Mercruiser Resources Collection

While you’re fixing your external engine components, make sure to keep the rest of your MerCruiser motor functioning its best by using PartsVu’s custom Gear Lube Kits, Mercury Drive System Parts, and 100 & 300 Hour Service Kits, available for all MerCruiser motors, MerCruiser inboard motors, and MerCruiser sterndrive motors.

Mercury Mercruiser External Engine FAQ

Are MerCruiser motor covers worth the investment?

We get it. Gear Lube Kits, Mercury Drive System Parts, and 100 & 300 Hour Service Kits MerCruiser motor covers are yet another thing you are told you need to buy for your engine. Are they necessary to protect your Mercury MerCruiser external engine parts?

One issue is cosmetic. Do you want your MerCruiser’s cowling to look new and shiny for as long as possible? Yet another issue is not cosmetic but is part of your overall effort to maintain your engine. Your MerCruiser’s cowling is like the skin on your body. Just as our skin does a great job of protecting our body’s systems, your cowling protects its own precious cargo—your engine.

Just as our skin takes a lot of abuse—sun damage, cuts, bruises, environmental contamination—so does your cowling. In the southern states, UV rays are especially intense. For example, boats and engines alike spend a lot of time baking nearly year-round in the Florida sun. In the northern states, boats may not be exposed for as many months of the year and the UV rays might not be quite as strong, but a lot of damage occurs.

Another source of harm is trailering. If you trailer your boat, your cowling is likely to be struck by stones, rocks, and other road debris as you tool down the highway. Scratches and dings are the low end of the damage—cracks and punctures in your MerCruiser cowling are more serious.

Finally, environmental elements like saltwater spray or acid rain could collide with your cowling at some point. MerCruiser covers do not eliminate all of these problems, but they sure do help a great deal.

How do I perform external engine maintenance for my Mercury MerCruiser motor?

Your MerCruiser engine’s external engine components need regular servicing during the lifespan of owning your motor. There are regular maintenance intervals that must be met for Mercury engines, including 20-hour service, every 100 hours, 300 hours, and so forth. 

The following is Mercury’s maintenance schedule for 100 hour and 300 hour maintenance intervals, including external engine maintenance and all other required tasks: 

100 Hours/1 Year

300 Hours/3 Years

How do I select the right MerCruiser part for my MerCruiser engine? 

PartsVu’s MerCruiser Maintenance Parts Library is designed to help you find the right MerCruiser parts for your particular engine to perform regularly scheduled maintenance - a must to keep your engine performing its best and to maintain your warranty. 

For MerCruiser motors, maintenance needs to be performed after 20 hours for new motors, then after 100, or 300-hours of service for optimal performance. Geared towards beginners and amateur mechanics, these maintenance parts charts are organized by each model number for MerCruiser’s line of 4-stroke engines.

To find the right specification and capacities, simply choose your engine model from a dropdown menu to see a complete list of details that include:

• Engine oil capacity
• Gear lube capacity
• Spark plugs
• Oil filters

Once there, you will choose the right parts for your MerCruiser by searching either by your outboard’s Primary Identification Number (PID) located at the top of this page. or look up your model using a series of dropdown menus on the left side of the page.

Choosing MerCruiser branded parts (OEM, or original equipment manufacturer) rather than after-market parts often yields the best results. If, for example, you install a defective aftermarket part and you experience a severe engine malfunction, you may void the warranty and ultimately end up spending much more on repairs in the future. For older MerCruiser models that are no longer supported by Mercury, there are plenty of parts available to fill this gap on PartsVu’s extensive catalog of MerCruiser-compatible parts.

How do I take care of my MerCruiser motor’s external engine parts? 

Corrosion is often the most common culprit of problems that external engine parts face. Due to the harsh aquatic environment - especially for saltwater boaters - moisture and other contaminants can degrade your engine’s components with only minimal exposure to the elements. 

Using Mercury Quicksilver Corrosion Guard is a smart decision to prevent all types of corrosion. Simply spray the product on all external engine components (except for the belts) to provide a layer of protection that’s corrosion-resistant all season long to salt accumulation and dirt to keep your engine ship-shape. Furthermore, using Quicksilver Corrosion Guard can also be used to prevent further paint damage in areas where undercutting and blistering have occurred.

Is winterizing my MerCruiser important?

While it’s always a bit more fun to pull out your boat than to put it away, properly winterizing your MerCruiser engine should be mandatory for all experienced boaters. Winterizing helps avoid engine damage and will facilitate a smoother start to the beginning of next season - after all, no one wants to wait to get back on the water!

There are several important steps you should take when storing your MerCruiser lower unit to ensure that it’s properly winterized.

1. Flush Your Engine - Thoroughly flush your MerCruiser engine to remove any salt buildup if you are a saltwater boater, or accumulated mud and grime if you are a freshwater boater. Failure to remove this debris from your MerCruiser lower unit leads to corrosion in the engine. And if you’re a saltwater boater, leftover salt crystals in the lower unit can act like sandpaper to your internal engine components.
2. Stabilize Your Fuel System - Fuel starts to go bad within 30 days of sitting in your MerCruiser fuel system. It is vital to use a fuel stabilizer like Mercury Quickstor Fuel Stabilizer when your boat will be sitting unused for more than two or three months. Adding the amount of fuel stabilizer directed on the product’s packaging to your fuel—for instance, 1 ounce of Mercury Quickstor Fuel Stabilizer for every 5 gallons of marine fuel ensures proper winterization for more than 3 months. 
3. Fog Your MerCruiser Engine - Mercury Storage Seal Fogging Oil is a wax-based oil that coats the engine to prevent corrosion.
4. Change Out the Lower Unit Oil - It’s recommended by marine mechanics to change your MerCruiser gear lube before storage to make sure that there is no water in the lower unit’s oil. Any water in the oil could freeze, expand, and crack your lower unit. Additionally, old oil is more likely to gum up oil passages and corrode components due to changes in its chemical composition through regular use. Last, consult your MerCruiser owners manual for which oil is appropriate for your engine.
5. Disconnect Your Battery - Disconnect your battery and spray CRC Marine Battery Terminal Cleaner on your battery terminals.