Advice: Oil Change. How? When? Why?

How? When? Why?

You need to change the oil in your bike not because it breaks down chemically but because the oil becomes contaminated. A litre of fuel produces about the same amount of water as a by-product.

When your bike's engine is at its normal operating temperature, the water vapourises and exits the scene via the exhaust valve(s). When your bike's engine is cold, though, some of this water vapour condenses and finds its way into the crankcase where it can create sludge and initiate corrosion. Acid is also produced in the combustion process as is soot, which can gum rings up and block the oil filter.

Another problem with cold running and lots of choke use is that unburnt petrol gets into the sump, diluting the oil and reducing its protective viscosity.

On top of all this, contaminant build-up in the sump can use up the service life of the additives in the oil designed to keep the inside of the engine clean and to keep contaminants in suspension.

HARD YARDS
In terms of oil life, there are a number of riding conditions which will affect it seriously. If you do lots of short trips with a cold engine (start the bike, ride it two or three kilometres with the choke on most of the way, stop it, let the engine go cold again, start it a few hours later, ride two or three kilometres again, then repeat the process on a regular basis), the oil won't do a particularly good job in protecting your bike's engine and will need to be changed more frequently than the bike manufacturer suggests. This kind of riding indicates you should use a light oil (10W40) and change it every 2500 - 3000km.

Similarly, if you do 200km every time you start your bike's engine and you ride flat-out, oxidation can occur and this reduces the effectiveness of the lubricant. This kind of riding suggests a heavier baseweight oil (20W60), a slightly longer warm-up period and similar change periods to those recommended for short, cold rides.

Between these two extremes, which is where most of us will do our riding, you can expect slightly longer oil life. Realistically, 5000km should be the upper limit, but 4000km is a kind compromise. Oil is relatively cheap, so feel free to alter your change periods to suit your riding conditions.

HOW
You only need a few tools and a tiny bit of information to change your bike's oil, so there's no excuse for not doing it yourself. You need your bike's owners manual (or a workshop manual) which will tell you where the oil comes out from (the drain plug) and where the fresh oil goes in afterwards. The owners manual will also tell you how much oil to use.

The only part you'll need for a simple change is a new washer for the drain plug which you can get from your local dealer.

In terms of tools, you need something to undo the drain plug. As these plugs are sometimes recessed, a socket with a ratchet handle is your best option.

While you're at your local dealer buying the $2.00 drain plug washer, ask them to tell you the size of the drain plug (for example, 17mm) and get them to show you where the drain plug is if you're not sure. Usually, it's the bolt at the lowest point underneath the engine. Ready to go? Take a spin on the bike so that the engine is hot before you start. This lets the oil drain freely.

Put your bike on its centrestand on a level surface and put something like a brick in front of the front wheel to stop any possibility of the bike rolling off its stand while you're under it.

Locate the drain plug and wipe the area clean with a cloth, remembering that the engine is hot and might burn you if you're not careful. Undo the drain plug one turn with the socket and ratchet handle. Bolts undo anti-clockwise and do up clockwise. It can be a bit confusing when you're on your back underneath the bike. You should expect the drain plug to be done up fairly tightly so it might require some effort to break the seal.

After you've loosened it, place a container under the plug to collect the oil which may already be starting to dribble out. You can usually undo the bolt the rest of the way with your fingers but remember both the bolt and the oil which will gush out when the bolt is removed will be hot.

Let it drain for half an hour or so, clean the plug, put the new washer on it and do it up again as far as you can with your fingers. The new washer will compress when you finish tightening the bolt with the socket. The drain plug should be done up firmly but not over-tightened. If you're using a short-handled ratchet, it's difficult to over-tighten.

Now you can pour the fresh oil in through the filler plug hole (your owner's manual will show you where it is).

Because you haven't changed the oil filter (do this every second oil change), you may need slightly less oil than the manual suggests. Use the sight glass or whatever means you have for checking oil level as a reliable guide.

Replace the filler hole cap, run the engine for a few minutes while the bike is still on its centrestand and then check the level again and underneath to ensure oil isn't leaking from the drain plug. It shouldn't make any difference, but I always think my bike runs better with fresh oil circulating in it!