How to Replace Oil on Your Mercury 4-Stroke

Marine engines are normally used over extended periods under intense UV rays and harsh saltwater. Furthermore, these marine engines normally also sit in storage in the off-season and usually out of use. Focusing on all the demands of your 4-stroke engine, you need to learn how to replace mercury oil and protect it from rigorous saltwater environments. These oils and lubricants have been specially engineered to provide your 4-stroke engine with many years of life, and here’s what you need to do.

Changing the mercury oil on your 4-stroke is quite simple. You can find the engine capacity and oil weight on your 4-stroke by looking under its cowling cover and locating the tag – or you could just read your owner’s manual. Before you can begin draining your old mercury oil, you need to check the level of oil on the dipstick. Next, you should lower the boat’s engine to its running position and then remove its cowling. With that out of the way, you can go ahead and remove the spent oil by removing your boat’s drain screw plug. After this, the extraction method will have you insert your vacuum extractor in the dipstick tube so you can pull out the old mercury oil.

If you’re extracting used oil in cold climates, then we would highly recommend that you warm-up your engine first. Doing so will make the old mercury oil thinner, making it easier to drain. While your vacuum extractor drains away from the old mercury oil, you should also unscrew the old oil filter so you can replace it with a new one. Before you ask, doing this will make your maintenance jobs less messy, and the technician’s method of puncturing the old filter just ruins your ability to inspect oil levels in the future. After you have disposed your old mercury oil and filter, reinstall your drain plug and spin on your new oil filter while making sure that it tightens up with its o-ring. After doing all of the above, it is finally time to add fresh mercury oil into the oil-fill plug at the very top of your engine. While doing so, keep looking at the dipstick while allowing the oil to pan out properly inside your engine. You should keep an eye on the dipstick so you can understand how oil levels change over time while your boat is being used. Wasn’t that easy?