EVERY MAINTENANCE ITEM: Mercury/Tohatsu 4HP/5HP/6HP 4-Stroke Outboard

Summary

The video script documents a DIY enthusiast's detailed process of maintaining a 2018 Mercury six horsepower four-stroke outboard motor. The individual shares their experience of performing various maintenance tasks, including an oil change, spark plug replacement, water impeller replacement, carburetor disassembly and cleaning, and lower end unit gear oil change. The script emphasizes learning and improvement, inviting viewers to contribute their insights and suggestions for better maintenance practices.

Takeaways

• 🧰 Basic maintenance on a 2018 Mercury 6 HP four-stroke engine includes oil changes, spark plug replacement, and water impeller replacement.
• 🛠️ For oil changes, use marine-grade 4-cycle 10W-30 oil and drain the old oil into a bucket, checking for metal shavings or contamination.
• 🔧 Replace the spark plug with a compatible E36 and tighten it to the recommended torque, even without a torque wrench.
• 💧 Change the water impeller annually to ensure proper cooling and prevent engine damage from lack of cooling water circulation.
• 🔄 Inspect the drive shaft and impeller housing for wear and ensure the impeller is correctly installed and keyed to the drive shaft.
• 🚫 Avoid changing gears while the lower end unit is detached to maintain proper alignment and prevent damage.
• 🛠️ Perform a carburetor disassembly and cleaning to address starting issues and improve engine performance.
• 🌊 Check the propeller for wear and clean the edges with a file to improve efficiency and prevent cavitation.
• 🔩 Reinstalling the lower end unit involves aligning the drive shaft, securing the water pump housing, and ensuring all connections are leak-free.
• 💰 Consider investing in a rebuild kit for the carburetor, which includes new gaskets and jets for a more thorough maintenance.
• 🚀 After completing maintenance, the engine should start more easily and run smoother, with improved performance and fuel efficiency.

Q & A

What is the main purpose of the video?

The main purpose of the video is to document and share the process of maintaining a 2018 Mercury six horsepower four stroke engine, including a carburetor disassembly and cleaning. The video aims to be a learning experience for both the creator and the viewers, and encourages comments with tips and advice for better maintenance practices.

How often should the oil be changed in the Mercury engine?

The oil should be changed every 100 hours of use, or at least once a season if the engine doesn't reach 100 hours.

What type and amount of oil is recommended for the 4, 5, and 6 horsepower Mercury and Tohatsu motors?

Marine grade 4-stroke 10W-30 oil is recommended for these engines, and they all take 15 ounces of oil.

What is the significance of sampling the used oil during a drain?

Sampling the used oil allows the observer to check for sediment, metal shavings, or any contamination that may have settled at the bottom of the oil, which can indicate potential issues or wear within the engine.

How often should the water impeller be changed in the engine?

It is recommended to change the water impeller every year. This helps ensure that the engine has proper cooling and prevents potential damage from running without cooling water circulation.

What is the role of the key in the impeller assembly?

The key fits into the impeller and locks it to the drive shaft, ensuring that the impeller spins and pumps water through the engine for cooling. Without the key, the impeller would not spin and the engine could be damaged due to lack of cooling.

What is the correct procedure for reinstalling the carburetor after cleaning?

After cleaning, the carburetor should be reassembled with the jets and gaskets in their correct positions, ensuring that the bowl is oriented correctly. The choke and throttle linkages should be reattached, and the carburetor should be bolted back onto the engine, making sure all vacuum and fuel lines are correctly reconnected.

How did the speaker address the issue of the prop not turning when attempting to start the engine?

The speaker realized that the shift linkage was out of position due to changing gears inadvertently while the lower end unit was decoupled. They fixed the issue by adjusting the coupling to ensure neutral was correctly aligned on both the motor side and the lower end unit.

What were the results after completing the maintenance activities?

After completing the maintenance activities, the engine started on the third pull when it was cold, and on the first pull once it was warmed up. The speaker noted an improvement in performance, particularly after filing the prop edge, and no longer experienced cavitation issues at full RPM.

What is the speaker's advice for future maintenance?

The speaker suggests investing in a pump for filling the lower end unit oil to avoid air pockets and ensure proper filling. They also recommend doing maintenance activities before winter storage and paying attention to details like the orientation of the carburetor bowl and the positioning of the key in the impeller.