Welcome to the step-by-step
guide to changing your outboard's lower unit oil. This 8-step process
is all it takes to ensure the oil in your lower unit is properly maintained.
The only tools required are a flat-head screwdriver and an oil drain
pan. The entire process only takes 10-20 minutes. We recommend you change
your lower unit oil at least once a year depending on how heavy the
usage is of your outboard. Any brand of oil that meets the specification
of API GL5 SAE 80 or 90 weight will work. You can find suitable oil
at your local marine dealer or automotive store.
The chart at the end of this guide lists the approximate amount of oil
needed to fill the lower unit of each model currently offered.
Step
one First, be sure your outboard is in a vertical and upright position. Locate and identify the upper and lower Fill & Drain Plugs. Place an oil drain pan beneath the outboard. |
Step
two Remove the BOTTOM drain plug first (not the top). Some oil will begin to trickle out so be sure your oil drain pan is positioned correctly to catch the draining oil. |
Step
three Next, remove the TOP drain plug. This will release the vacuum that exists and allow the oil to drain freely from the lower unit. |
Step
four Let all of the oil drain completely from the lower unit (this will take about 5-10 minutes). |
Step
five
|
Step
six Continue adding oil until the lubricant is flowing freely from the top hole and is free from air bubbles. |
Step
seven Keep the bottle/tube in the bottom plug (or plug the hole with your finger) and re-install the TOP plug. This will create a slight vacuum that will minimize the oil loss while you reinstall the bottom plug. |
Step
eight Now, QUICKLY remove the bottle (or your finger) from the bottom hole and install the drain plug. It is important to do this as quickly as possible to minimize the amount of oil loss. Even though there is a slight vacuum, there will still be some loss of oil. Do not be concerned about losing some oil, however, if you lose an excessive amount of oil you will need to go back and add additional oil. Hand tighten both the lower and upper drain plugs and wipe off any oil on your lower unit. |
WARNING: Running your
outboard without completely filling the lower unit with oil to
the proper level will cause severe damage to your outboard. See
the comments at the end of this guide on how to check for the
proper oil level in your lower unit.
Be sure and properly dispose of your old oil by taking
it to an oil recycling center. Most "quick lube" oil change centers
or auto service stations will accept your used oil for a nominal
fee.
Comments: To check your oil level, remove the top oil plug,
insert a small piece of wire straight into the top hole approximately
1 inch and withdraw the wire. If oil is on the wire the oil level
is correct, if not the unit must be refilled to the correct level.
To add ("top-off") oil install the top plug again, remove
the bottom plug and put your oil bottle into the hole. Remove
the top plug to release the vacuum and add the necessary amount
of oil. Reinstall the top plug, then quickly reinstall the bottom
plug. Check the oil level once again as described above.
| Lower Unit Oil Needed by Model | |
Model |
Approximate Fluid Ounces Required |
| 2A & 3.5A (4-stroke) | 6.1 fl oz |
| 2.5A & 3.5A (2-stroke) | 3.0 fl oz |
| 3.5B (2-stroke) | 6.0 fl oz |
| 4 (4-stroke) | 6.6 fl oz |
| 5 (2-str/4-str) | 6.6 fl oz |
| 6 (4-stroke) | 6.6 fl oz |
| 8 (2-str/4-str) | 10.8 fl oz |
| 9.8 (2-str/4-str) | 10.8 fl oz |
| 9.9 (2-stroke) | 12.5 fl oz |
| 9.9A (4-stroke) | 6.8 fl oz |
| 9.9B (4-stroke) | 12.5 fl oz |
| 15 (2-stroke) | 12.5 fl oz |
| 15A (4-stroke) | 6.8 fl oz |
| 15B (4-stroke) | 12.5 fl oz |
| 18 (2-str/4-str) | 12.5 fl oz |
| 25 (2-stroke) | 14.5 fl oz |
| 25 (4-stroke) | 9.5 fl oz |
| 30 (2-stroke) | 14.5 fl oz |
| 30 (4-stroke) | 9.5 fl oz |
| 40C (2 cyl) | 15.9 fl oz |
| 40D (3 cyl) | 16.9 fl oz |
| NSD40 (TLDI) | 16.9 fl oz |
| 50D (3 cyl) | 16.9 fl oz |
| NSD50 (TLDI) | 16.9 fl oz |
| 70B (3 cyl) | 23.7 fl oz |
| 70C (3 cyl) | 30.4 fl oz |
| NSD70 (TLDI) | 30.4 fl oz |
| 90A (2-stroke) | 30.4 fl oz |
| NSD90 (TLDI) | 30.4 fl oz |
| 115A (2-stroke) | 30.4 fl oz |
| NSD115 (TLDI) | 30.4 fl oz |
140A (2-stroke) |
30.4 fl oz |




