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Marine Engine Maintenance

Marine Engine Maintenance How-Tos

How to Change The Oil On Your I/O Boat

  1. Step 1 - Warm the Engine
  2. Step 2 - Drain the oil
  3. Step 3 - Replace the filter & the Plug
  4. Step 4 - Add the new oil
  5. Step 5 - Check all the oil levels

How to Change the Gear Oil

  1. Raise out drive to up/out position, like when trailering.
  2. Empty monitor reservoir/tank.
  3. Remove lower & upper drain plugs, in that order.
  4. Lower out drive and let lube drain out.
  5. Pumplube until visible in upper vent hole.
  6. Replace upper vent plug.
  7. Pump lube until visible in monitor reservoir/tank.
  8. Replace lower fill plug.
  9. Top up monitor reservoir/tank.

First step is to raise the engine to its upright position similar to its position when trailering. Removing the monitor tank on your motor comes next, remove the strap holding it in place to make this next step easier. Remove the lid and empty the tank into a container, and not on the ground. Be cautious for the surrounding wires, and make sure not to spill on anything. After emptying, put the lid back on and strap in to place so that you do not lose any parts.

Now we move around to the out drive for step 3, which is removing the lower drain plug. Be careful when doing so, and have a bucket ready, gear lube may start to squirt out when removing the plug. Remove the drain plug using a screw driver, be careful not to lose the washer surrounding the screw. With that being done, we want to remove the upper vent plug using a screw driver. When you remove the vent plug, the lube will start flowing much more from the lower unit.

Next step is to lower your out drive for the lube to drain out. Use a gear lube pump to fill the motor back up. Make sure you're using the proper pump for your motor, and follow the pumping directions. Most likely you will need more than one bottle of lube, and are probably wondering how you would switch them out. Put the upper vent plug back in a little bit so that air cannot enter and push the lube out. Once you have the bottles of lube switched out, remove the vent plug and continue pumping lube back in. Stop pumping when you see lube begin to flow out of upper vent plug. Once this happens, screw the plug back in so that you can pump lube into the monitor tank.

Now that you're ready to fill up the monitor tank, remove the lid and strap holding the tank in place. Begin pumping until you see the tank fill up with the lube you have left over. After the bottle of lube has finished, place the lid and strap back on the tank. Placing the lid back on the tank locks the air in place and allows you to remove the lube pump you are using. Be careful when doing so, as some lube may still leak out. The best practice is to have your screw and washer ready in one hand, while removing the pump hose with the other.

The final step is to top off the monitor reservoir/tank. If you have any additional questions, please be sure to check out our Boating Forums.

Boat Tune-Up Check List

While cleaning your boat is important to maintain its appearance, it is equally important to pay attention to the mechanicals because it will help ensure that the fun stops and starts when you choose. If your boat has been sitting in storage, do a thorough check before taking it out on the water, as it will save you time and money to diagnose issues upfront.

  • Flush it:Purchase an engine flusher, attach a garden hose and run fresh water through the engine, which should come out the air vent holes. Then, start the engine so the water circulates. Once the water starts to come out warm, turn off the engine.
  • Check Hoses:If you disconnected any hoses while the boat was in storage, make sure to reconnect them properly using your owner's manual.
  • Refresh Fluids:Make sure to check your fluid levels, including oil, gas and coolant and ensure your gearbox is properly lubricated. When refilling your gas tank, it's a good idea to add an ethanol treatment to your gasoline to address ethanol-related issues that can cause severe damage to your engine, such as Marine Formula STA-BIL. Add ethanol treatment to fresh fuel at every fill-up. If your boat has been sitting for more than 30 days with unstabilized fuel, drain the gas tank completely and refill with fresh fuel and an ethanol treatment.
  • Spark Plugs:Check, and if necessary replace your boat's spark plugs after storage to keep it running its best.
  • General Inspection:Do a quick inspection of your propeller to make sure there are not any issues with the propeller. Major cracks gouges etc. should obviously be repaired. Make sure the retainer nut is properly torqued and that the retainer pin/washer is in place and working properly. You should also take a look at your air filter to see if it needs replacing. If you didn't get around to an oil change at the end of the season, you should strongly consider doing one now.

Once you've tackled this check-list, your boat should be all spruced up and ready to head out on the water. Be safe, have fun and enjoy!

Ethanol treatment products and other great Gold Eagle products can be found at iboats.

Tom is director of marketing at Gold Eagle Co., industry pioneer and maker of America's No. 1 selling fuel stabilizer, STA-BIL®, and 303® Products. Tom has six years of experience in the performance chemical industry and seven years in the outdoor power equipment industry and is a certified small engine mechanic.