Mercury Outboard Complete 100 & 300 Hour Service Kits

Mercury 100 & 300 Hour Marine Engine Service Kits Resources and Information

PartsVu.com is proud to offer certified Mercury 100-hour and 300-hour outboard service kits. These kits include parts and products such as: Mercury outboard oil filters, Mercury gear-case drain seals, Mercury gear lube, Mercury thermostat kits, Mercury fuel filters, NGK spark plugs, Mercury anodes, belts, Mercury water pump repair kits, Mercury in-line fuel filters, Mercury fuel rail filters.

Browse the rest of our complete selection of Mercury outboard parts, or shop the rest of our service maintenance kits by Mercury outboard model, including: 

 

Mercury 40 - 50 - 60 HP EFI 4-Stroke Maintenance Kits

Mercury 150 HP EFI 4-Stroke 100 & 300 Hour Maintenance Kits

Mercury 200-225-250-275-300-350 Verado L6 100 & 300 Hour Kits

Mercury 200-225-250-300 V8 (4.6L) 100 & 300 Hour Maintenance Kits

 

We also offer helpful resources to help you maintain your Mercury outboard motor, such as:

• Mercury Outboard Engine Schematics
• Mercury Outboard 100-hour Service Guides
• Mercury Outboard Specs & Capacities Chart

Mercury 100 & 300 Hour Outboard Service Kits FAQs

How do I service my Mercury 4-stroke outboard fuel system?

Use a filter wrench to loosen the existing filter element and use caution when removing it as it will be filled with gasoline. A clear plastic or glass container is helpful to dump the filter and examine the contents. A small amount of debris is common, as is a small amount of water after the fuel has had a moment to settle. More significant amounts of water would warrant further investigation.

Move back to the engine and locate the filter element(s) on the engine. The scope of this service will only include the low-pressure fuel filter and fuel water separator if applicable by model. Mercury recommends that owners do not service their high-pressure fuel filters. Depending on your engine model, the water separator filter (or castle filter) may be removed by using a wrench, standard tools, and a little caution. Unplug the water-in-fuel sensor if applicable and spin the cap off of the housing. Replace the filter element with a fresh one, lube the o-ring with grease or oil, and carefully reinstall the cap.

Locate your Mercury engine’s primer bulb if applicable and use the primer to pump up the fuel system. You should feel and hear gasoline entering and filling the filter cup. Check for leaks and prime until the bulb becomes firm.

If you are not already regularly running Mercury Quickare and/or Quickleen through your Mercury fuel system, the 100-hour service interval is an excellent time for a “shock treatment.” Quickare is a fuel system cleaner and top-lube that will help to clean deposits from the tank, lines, carburetors, injectors, and pumps. It breaks up fuel system varnish and will help to prevent gumming.

Quickleen is a fuel system conditioner that also helps to remove carbon deposits. The standard dose is one ounce per ten gallons, but if you are not running the product regularly, you can double that ratio for more cleaning power. Pour the products into the fuel tank fill and run the boat. No additional work is needed. It is a great idea to inspect your fuel tank fill’s o-ring for damage when you add fuel or additives as a damaged o-ring can allow water from rain or boat washing into your fuel system.

How do I perform an oil change on my Mercury 2-stroke outboard motor?

Engine oil selection is critical to long life, so review the information in your owner’s manual to make certain you are using the correct products. Not all TCW3 oils are formulated the same, and different Mercury models do prefer specific oils. Mercury Marine offers a wide assortment of engine oil – both in blend and additives. If you are uncertain exactly which oil is best for your application, consult your owner’s manual.

If you do locate contamination in the oil tank, use a vacuum extractor to pull the remaining oil out of the tank for proper disposal. While good quality two-stroke oil is certainly expensive, running contaminated oil can lead to catastrophic failure. If you have never cleaned the bottom of your tank, prepare to be surprised by what you find.

Several laboratories provide performance testing of used oils, allowing you to learn more about the health of your engine. Blackstone Labs is one such provider, and they have a convenient mail-in kit that includes everything you need to submit an oil sample. They can also test gear oils, hydraulic fluids, and oils from your other vehicles or toys. 

How do I change my Mercury 4-stroke outboard engine oil?

As the old oil is draining, you can work on removing the engine oil filter. Depending on your specific Mercury model, your filter may have a drain lip that helps to keep the mess to a minimum when you unscrew the old filter. However, most older engines do not have this feature. We suggest being prepared with plenty of absorbent rags or placing a small cup that is cut to size below the filter before removal. Using a PartsVu Maintenance Essentials filter wrench is the best way to loosen the filter. Remember when you reinstall the filter, over-tightening will only make your life more difficult when you are ready for the next service. Some technicians puncture the old filter allowing trapped oil to drain back into the block before removal, but this will ruin your ability to take the filter apart for further inspection.

Several laboratories provide performance testing of used oils, allowing you to learn more about the health of your engine. Blackstone Labs is one such provider, and they have a convenient mail-in kit that includes everything you need to submit an oil sample. They can also test gear oils, hydraulic fluids, and oils from your other vehicles or toys. Oil test results can tip you off to an accelerated wear condition inside of your engine long before any other symptoms show up. If you still want to know more about your engine, purchase an oil filter cutter and open the spent filter to look for evidence of contamination and metal dust or shavings.

Once you have inspected your spent oil and filter, set them aside for proper disposal. If you removed the drain screw to empty your oil, carefully reinstall the drain plug. The new oil filter should be removed from its package and the o-ring lubricated with a thin coat of fresh engine oil. Spin on the new oil filter and gently tighten to seat the o-ring without over-torquing.

Mercury Marine offers a wide assortment of engine oil – both in blend and viscosity. If you are uncertain as to which oil is best for your application, consult your owners’ manual. Loosen the yellow oil fill plug on the top of the engine and pour in fresh oil. We recommend adding slightly less than the stated capacity. With the engine trimmed down, check the oil level on the dipstick after allowing a few minutes for the oil to drain into the oil pan properly. Filling the oil to the lower level on the dipstick will help you to measure if the oil level changes over time with the engine in operation.

How do I service my Mercury 2-stroke outboard motor grease points?

Note that fittings can be contaminated by salt – especially the ones near the steering tube – so replace them if they are too corroded to accept grease. Watch as you pump fresh grease into the fitting and see if old, dirty grease or water or both push out from the corresponding space. Ideally, these cavities are filled with clean grease all the time. A light coating of grease on the tip of the trim rams will reduce friction there as well. If your engine is equipped with stainless balls on the tips of the trim rams, work the balls to get the grease inside their cup.

If your prop was not removed for the gear lube change, remove the cotter pin or lock washer from the propeller and loosen the prop nut. Exercise extreme caution as prop blades can be very sharp. With the nut loosened, remove the propeller and associated prop hardware to inspect the propeller shaft.

Look for fishing line that may be behind the prop and near the prop shaft oil seals. Remove any line and if the seals are intact, apply a fresh coating of Mercury 2-4-C grease to the propeller shaft before reinstalling the prop. Tighten and use a new cotter pin to complete the installation if applicable.

Can I service my own Mercury outboard?

Yes, you can service your own Mercury outboard if you have the necessary knowledge and experience. However, it is recommended that you refer to the owner's manual and follow the recommended maintenance schedule to ensure that your outboard is properly maintained and in good working condition.

How many hours does it take to break in a new Mercury outboard?

The break-in period for a new Mercury outboard can vary depending on the model and size of the engine. It is recommended that you refer to the owner's manual for specific instructions on how to break in your outboard. Generally, the break-in period can range from 10 to 20 hours of operation, during which you should avoid running the engine at full throttle or high speeds.

How often do you change spark plugs on a Mercury outboard motor?

The recommended interval for changing spark plugs on a Mercury outboard motor can vary depending on the model and year of the engine. It is recommended that you refer to the owner's manual for specific instructions on when to change the spark plugs. In general, it is recommended to change the spark plugs every 100 hours of operation or at least once a year, whichever comes first.

How often should a Mercury outboard be serviced?

The recommended service interval for a Mercury outboard can vary depending on the model and year of the engine. It is recommended that you refer to the owner's manual for specific instructions on when to service your outboard. In general, it is recommended to service your outboard at least once a year or every 100 hours of operation, whichever comes first. Regular maintenance can help ensure that your outboard is running smoothly and can help prevent costly repairs down the line.

What's not included in a Mercury 100 hour service kit versus Mercury 300 hour service kit from  PartsVu?

The exact contents of a Mercury 100 hour service kit and a Mercury 300 hour service kit can vary depending on the specific model and year of the engine. However, in general, a 100 hour service kit typically includes items such as oil filters, fuel filters, spark plugs, and other components that need to be replaced at regular intervals.

A 300 hour service kit may include additional components that are typically replaced at longer intervals, such as water pump impellers, thermostats, and other components that require less frequent maintenance. It may also include additional lubricants or fluids that need to be changed less frequently than the engine oil.

It's important to note that not all maintenance items are included in either the 100 hour or 300 hour service kit, and additional maintenance may be required depending on the specific condition of the engine. For example, the timing belt or other components may need to be replaced if they show signs of wear, even if they are not included in the service kit.

Is there a difference between a Mercury maintenance kit versus a Mercury service kit?

Yes, there is a difference between a Mercury maintenance kit and a Mercury service kit.

A maintenance kit typically includes components that need to be replaced at regular intervals to maintain the performance and reliability of the engine. These components may include items such as oil filters, fuel filters, spark plugs, and other consumable items that require periodic replacement.

On the other hand, a service kit typically includes components that are required for more in-depth maintenance or repairs. These may include items such as water pump kits, impellers, thermostats, gaskets, and other components that are typically replaced less frequently than the components included in a maintenance kit.

It's important to note that the specific contents of a maintenance kit or service kit can vary depending on the specific model and year of the engine. It's always a good idea to refer to the owner's manual or consult with a qualified Mercury technician to determine the specific maintenance or service requirements for your engine and to ensure that all necessary components are included in your kit.

What is a Mercury outboard service kit?

A Mercury outboard service kit is a pre-packaged kit that contains all the parts needed to perform a maintenance service on your Mercury outboard engine. The contents of the kit can vary depending on the specific needs of the engine, but typically include things like oil filters, fuel filters, spark plugs, and other consumable parts.

Why should I use a Mercury outboard service kit?

Using a service kit ensures that you have all the necessary parts for your engine's specific maintenance needs. It also saves time and money compared to purchasing each individual part separately. Additionally, service kits are often designed by the engine manufacturer to meet their specific requirements, ensuring that you are using high-quality parts that are compatible with your engine.

How often should I use a Mercury outboard service kit?

The frequency of service for your Mercury outboard engine depends on several factors, such as usage, environment, and the specific model and year of your engine. However, it's generally recommended that you perform a maintenance service at least once a year or every 100 hours of operation, whichever comes first. Using a service kit can make this process quicker and more convenient.

Are all service kits the same for every Mercury outboard engine?

No, the contents of a service kit can vary depending on the specific model and year of your Mercury outboard engine. It's important to ensure that you are purchasing a service kit that is compatible with your engine. You can consult your owner's manual or a qualified Mercury technician to determine the appropriate service kit for your engine.

Where can I purchase a Mercury outboard service kit?

Mercury outboard service kits are available through authorized Mercury dealerships and through various online retailers, such as PartsVu.com. It's important to ensure that you are purchasing a genuine Mercury service kit from a reputable source to ensure compatibility and quality.

Are MerCruiser service kits the same as Mercury service kits for outboards?

No, MerCruiser service kits are different from Mercury service kits for outboards. MerCruiser is a separate brand from Mercury and produces inboard and sterndrive engines, while Mercury is primarily known for their outboard engines. The two brands have different maintenance requirements and service kits, so it's important to use the appropriate kit for your specific engine. It's recommended to consult your owner's manual or a qualified technician to determine the appropriate service kit for your MerCruiser engine.

How to tune up a 2 stroke outboard motor, and what service kits are available?

Here's a guide to tuning up a 2-stroke Mercury outboard motor, along with information on the Mercury 2-stroke outboard service kits that are available:

1. Replace the spark plugs: The first step in tuning up a 2-stroke Mercury outboard is to replace the spark plugs. This should be done every 100 hours of operation or at least once a year. The Mercury 2 stroke service kit typically includes spark plugs.
2. Inspect the fuel system: Check the fuel lines, filters, and tank for any signs of damage or wear. Replace any components that appear to be in poor condition. The Mercury 2-stroke service kit may include fuel filters and fuel pump kits.
3. Check the water pump: The water pump is responsible for cooling the engine, so it's important to make sure it's working properly. Check the impeller and replace it if it appears to be worn or damaged. The Mercury 2-stroke service kit may include a water pump kit.
4. Inspect the lower unit: Check the oil level in the lower unit and replace it if it appears to be dirty or contaminated. Inspect the propeller for any signs of damage or wear. The Mercury 2-stroke service kit may include lower unit oil and a replacement propeller.
5. Adjust the carburetor: If your 2-stroke Mercury outboard is not running smoothly, you may need to adjust the carburetor. This can be done using a carburetor adjustment tool. The Mercury 2-stroke service kit may include a carburetor rebuild kit.

In terms of service kits, Mercury offers a range of 2-stroke outboard service kits that include everything you need to service your motor, including spark plugs, fuel filters, water pump kits, lower unit oil, and carburetor rebuild kits. The specific kit you need will depend on the model and year of your outboard. Some popular options include the Mercury 2 stroke outboard service kit and the Mercury 2-stroke service kit.

How much does it cost for 100 hour boat service vs 100 hour outboard service?

The cost of a 100-hour boat service versus a 100-hour outboard service can vary widely depending on a number of factors, including the type of boat and outboard motor, the service provider, and the specific services included in the service package.

Generally speaking, a 100-hour boat service will typically involve more comprehensive maintenance tasks, such as inspecting and servicing the boat's electrical and mechanical systems, cleaning and inspecting the hull and underwater gear, and performing any necessary repairs or upgrades. This type of service can range from a few hundred to several thousand dollars, depending on the size and complexity of the boat and the extent of the service package.

On the other hand, a 100-hour outboard service typically involves more focused maintenance tasks on the outboard motor itself, such as changing the oil and filters, inspecting and servicing the propeller and lower unit, and inspecting the ignition and fuel systems. The cost of a 100-hour outboard service can range from a few hundred to a few thousand dollars, depending on the make and model of the outboard motor and the specific services included in the service package.

It's important to note that these are just gener

Where can I learn more about Mercury Outboard Parts?

PartsVu understands that boaters want to learn how to perform their own Mercury outboard maintenance. From maintaining your Mercury outboard, Mercury sterndrive, and MerCruiser engines, there’s always something new to learn and save money. That’s why PartsVu offers our comprehensive blog, The Partsvu Xchange. 

Read up on the latest developments in boating, as well as search for everything you need to know about Mercury engine maintenance.

To get you off to a good start, these are some of the most popular important articles for using Mercury 100 & 300 Hour Service Kits and much more:

• How to Check Hours on a Mercury Outboard - PartsVu
• Maintaining Your Mercury Outboard Water Pump
• Mercury Grease Points - 4-Stroke 100-Hour Service
• How to Select the Right Mercury Outboard Parts

Is a Mercury lower unit drain plug gasket included in a Mercury service kit or an Mercury oil change kit?

The inclusion of a Mercury lower unit drain plug gasket in a Mercury service kit or oil change kit can vary depending on the specific kit that you purchase. It's important to carefully read the product description or check with the manufacturer or seller to ensure that the kit includes all the necessary components. If you need a lower unit drain plug gasket and your kit doesn't include it, you can typically purchase one separately from Mercury or from a third-party supplier like PartsVu - a leading online retailer of marine parts and accessories.