How do you change oil on a Mercruiser 470?

Answer 1

1) Remove the old oil by either draining it out the oil drain plug or by purchasing an oil pumpout kit and pumping out thru the dipstick tube. If draining, the oil drain plug is clearly visible on the starboard side of the oil pan (look toward the bottom, left, rear of engine while facing the back of the boat). If removing via the drain plug, you will need a means of catching the oil after removing the oil plug. You can purchase a kit which can be permanently installed to your oil drain and allows you to snake a tube out the bilge of the boat so that the oil can be directed into a remote container. Alternatively, you can fabricate something to fit in the space between your bilge and the drain to catch the oil (a heavy duty trash bag can be maneuvered into tight spaces in a pinch but use caution if the engine is hot).

2) Replace the oil filter which is also clearly visible on the starboard side of the engine. It should come off by hand or use an oil filter wrench. When installing the new filter, hand tighten only (do not use wrench) and remember to spread oil on the gasket of the new filter before screwing it on.

3) Add your fresh oil thru the cap on top of the engine marked "oil". Remember to put the oil drain plug back on first if you removed in step 1. It may take up to 5 quarts if fully drained in step 1. Type of oil depends on where and when you use your boat. Note that single grade oil (HD30/HD40/etc) is recommended over multi-viscosity (10W-30/etc) used in autos. After filling start the engine for 10 seconds to allow the new oil to spread thru the cylinders. Recheck the oil level periodically and top off as needed.