Boats & Motors
Why Drain Your Lower Unit
I have changed by 40 hp 1997 4 cylinder yearly since new. Never had water in the oil and looked near new each time draining it, but not perfect with the first time way back in 1997 some metal filings on the drain plug, not much though. Never have ever replaced the o-ring washer ever since looked as good as new, but others replace that every 2-4 years or so. I use my boat sparingly like 4-10 times each summer, so really not needed to do every year in my opinion. If I was using it 15-25 times per year, then I can see changing gear lube once every year. It is that one time that water comes out first that you will regret and then if that happens, replace the rubber o-ring for sure. Cheap insurance with the bottle pump that threads onto the bottom plug, easy to do and cheap but not needed for me really every year, more like once every other year for low use like mine, but I do it anyways since easy and fog my engine by running it in a 32 gallon trash container filled with water in my yard and take cover off, let engine warm up fully, take a can of mercury spraying fog oil with red long wand attached and spray into the 2 carbs back and forth full spray and then disconnect gas line and keep spraying fogging oil back and forth into carbs both top and bottom one and rev engine a bit while doing this until you see a cloud of smoke rise up behind the engine until the engine eventually dies due to lack of gas and too much fogging oil. Then, take out spark plugs (I have 4 for my 4 cylinder), clean the gunk buildup on plugshem with fine very tiny flat screwdriver, squirt a few sprays of fogging oil into the spark plug holes, turn over engine by hand cranking it on top a few times, and reinstall plugs, put cover back on and good to go all winter long. I put so much fogging oil in that the oil runs out the prop on bottom and makes a mess without putting newspaper and cardboard on your garage floor once you lower the engine fully.
The real danger is from water in the lube. Enough water can crack housings or push seals out of place. Depending on the horsepower of your motor, the lube breaks down over time and can cause accelerated ware on the gears. If no water is present and you dont use the motor much, you may be able to run several years on a refill. rebuilding a gear case is expensive so its just good practice to drain and refill every year. DO NOT LEAVE EMPTY OVER WINTER!!! This will invite rust and pitting on the gears and bearings.
another with changing oil in 4stroke and lower unit again
I also change out the gasgets on the drain screws
On my Etec, only thing I have to do is push a button to fog the engine and it is winterized in less than 2 min, and if I want to go back out for late season eyes, no problem. Just pull back into garage and winterize again. Every engine I have owned I change lower unit once a year...normaly in the spring when I take it out of stoarage. VERY cheap and less than 5 min of work to do and could save you thousands $$$$$.
This statement is my own personal opinion and in way reflects the thoughts or views of BRP and all brands including but not limited to Evinrude/Sea-Doo/Ski-Doo/Can-Am.
If you drain your lower unit oil, don't just wait to fill it up next season either. There are many reasons to fill it right away, but the best one I can think of is something that a friend of mine did. It was spring and he was pumped to go fishing. Hitched up the boat and headed out. He didn't get far from the dock when he realized he had no oil in the lower unit. He's the only person I know who never filled it right away lol!
