Motorcycle Oil Change: YZF R-125

Oil changes are a brilliant thing you can do to your bike to keep the engine happy and give your bike the best chance to have a nice long life, and they don’t need to cost a lot if you’re willing to learn and do them yourself.

So lets get our hands dirty and show you how I do mine. This isn’t guarantee to be the same on your bike but a lot of this content will be transferable and hopefully it’ll share a trick or two I’ve found in my time on bikes.

First things first, you’re going to need a few things, it is the worse thing to be stuck half way through a job and find you’re missing something. a wise man once told me that failing to prepare is preparing to fail.
Make sure you have all the tools you are going to need, make sure you have a clean filter, the correct engine oil, space to work and enough time to complete the job – an oil change takes me around twenty to thirty minutes, if you are taking this on for the first time allow for maybe double this time so you can take your time.

To change your oil specifically on a YZFR-125 you will need the following;

One litter of 10W40 Engine oil, the correct oil filter, paper towels, 19mm socket & ratchet or spanner depending on your preference, an 8mm & 12 mm and a 13mm socket & ratchet or spanner again depending on preference, size 4 Allen key, lighting, Tinfoil and a catch tray for the old oil. If you have a nice little tool kit that is entry level you will probably have all of these tools. One last thing that isn’t essential but nice to have is a torque wrench. For the best and easiest way to work a rear stand is a great thing to have Oh and some cable ties, you’ll find out why in a moment.

  • The first thing I do is tidy up and make enough space to get down next to the bike.
  • Get enough light in the work area
  • Put some cardboard down to protect the floor
  • Get the bike in place
Front brake cable tied


Once everything is in place I put a piece of wood under the side stand to lift the bike up straight, a cable tie the front break on so the bike doesn’t move, straighten the handlebars and then i lift the back end up with the rear stand. This little trick just helps you put the bike on a stand safely and securely especially if you are on your own.


Next i strip the fairings off, you will need that size four Allen key or like me a ratchet with an Allen head bit. Tip – Put all the fairing bolts back in the threads to avoid loosing them or ending up with ‘spare parts.’


Bolt back in the threads

on the belly pan there are three push bolts, the trick to these are to use a small pointy tool to push the center of them and then pull them out – I tend to use a small Allen key.

Once everything is out of the way make sure you put the fairings somewhere safe as they can be expensive things to replace.

Now comes the annoying part, if like me you have an after market exhaust, chances are the down pipe is in the way of the sump plug, the easiest way to get around this I have found is to loosen the header bolts (12mm) and then remove the first brackets bolt (13mm), this will allow you just enough space without taking the exhaust off completely which isn’t hard to do but it’ll just add time on to the job. Once the exhaust is loose wrap tinfoil around the down pipe to help protect the pipe work from the oil that is going to drain.

Foil over the down pipe

Now make sure the drip pan or catch tray is in place as we are now ready to drain the old oil. first thing I do is remove the filler cap, this allegedly helps drain the engine faster. Now I get my 19mm socket and ratchet and remove the sump plug, be warned this may be very tights so you may want to use a long arm/ breaker bar or like me slide a piece of pipe over your ratchet handle for the leverage (I wouldn’t necessarily suggest this as the best method but i’m a cheap skate and decided it was good enough for me).

Make sure that once the sump plug is removed you get all three parts; spring, sieve type mesh and the plug itself. It is always good to change the seals on anything you remove during an oil change (Filler cap/ dipstick, filter cover, sump plug) you can pick up a set of seals rather cheap off the Internet.

while you leave this to drain you can remove the filter cover and you will need your size 8mm socket for this, note that one bolt is much longer than the other two and it must be replaced to the same place or reassembly (bottom right).

once the cover is removed also remove the old filter and clean the inside of the filter housing with a piece of kitchen roll/ paper towel. I usually leave this to drain and go make a cup of coffee to warm myself up a little and give the engine a good chance to drain fully.

Once the engine is completely drained as much as it is going to be i replace the seal on the oil filter cover and replace the filer.

New seal & Filter

Once the engine is completely drained as much as it is going to be i replace the seal on the oil filter cover and replace the filer.

I return this to the bike and make sure I don’t over tighten the correct torque setting is 15 newton meters but my torque wrench doesn’t measure that low so i do them hand tight and give each nut a pinch with a spanner.

Next I give the sump plug a nice new seal after cleaning all three components. and then i return it to the bike. the correct torque setting is 33 newton meters.
If you struggle returning the sump plug try laying on the floor along side your bike and with a socket offer up the sump plug. this may give you better grip. Be careful though if you struggle to get the sump plug back in do not force it and cross the threads this would make for a real pain in the backside.

Using a funnel I pour One litter of oil in to the engine, if you are changing your oil and not replacing the filter then add less but i always like to change the filter, once it has a liter in i return the filler cap/ dipstick with a new seal.

Finally after all this i return the exhaust back to how it should be and make sure it is secure. Also remove the tinfoil.

Oh and don’t forget to remove the cable tie from the front brake once you have removed the rear stand.

It is worth noting also that although I change the seals every I do an oil change it is not required it is just good practice and i would never recommend you to ignore the seals but if you don’t change them every oil change keep an eye on them for signs of failure, if the seals look heavily worn it would be a good time to change them.

Now everything is back in place start the bike up and let it get to operating temperature if you get an error message Er-1 With an oil light turn the bike of and turn it back on again if the error has cleared your oil filter just needed a chance to fill up with oil. while the bike is idling inspect the sump plug area and the oil filter cover for signs of leaking, if any oil seeps out try just tightening the nut if possible.

Since the bike has not got an oil viewing window the only way to see you have enough oil in is check for an oil light on the dash and check the dipstick (with the engine off).

All in all for the sake of half an hour and the cost of an oil filter and a liter of oil you will save yourself a fair bit of money over the year. And since I am a cheap skate I usually buy four litters and measure out a litter at a time as it works out even cheaper.

So if you’re willing to learn and get your hands dirty save yourself some money and get to know your machine a little better.

Just to reiterate this is specific to the Yamaha YZF R-125 but a lot of this information will be transferable to most bikes,  I hope you have found this informative, leave a comment to let me know what you think.