Checking your oil level. The oil level check procedure for your Yamaha four-stroke outboard is a bit different than the procedure for your car. It’s easy to get an accurate reading if you follow this procedure:
Start and warm the outboard to normal operating temperature, then shut it off. Stop the outboard.
Tilt engine up halfway and allow to rest for 5 minutes to thoroughly drain the oil back into your outboard’s crankcase.
Trim the outboard back down to level.
Tip: You can place a small level on top of the anti-ventilation plate to help you determine when to stop.
Pull the dipstick, wipe the oil from it, and re-insert it in the crankcase. Then pull the stick again and check the oil level. This helps ensure proper venting for accurate indication.
At the proper oil level, the oil should be halfway up crosshatch pattern on the dipstick.
Tip: The top and bottom of the crosshatch pattern on the dipstick do not represent “high” and “low.” The correct oil level indication is at the mid-point of the pattern. Use caution when filling or adding oil. Yamaha four-stroke outboards have a tapered oil sump design (smaller at the top than the bottom), so the closer the oil level is to full, the faster it fills. Therefore, add oil slowly and in small amounts, and do not attempt to “top off.” Do not allow the oil level to surpass the upper portion of the crosshatch pattern. Doing so may result in aeration of the oil, reducing lubricity and oil pressure, and may cause eventual engine damage.