How to Check Motorcycle Oil: Dipstick & Inpection Window

How to check motorcycle engine oil

Whether you ride a shaft drive motorcycle or a chain-drive classic, it's essential to check your engine oil regularly. That's because every motorcycle engine needs an appropriate level of the right oil - in the right condition - in order to give you the performance, economy and reliability you deserve. Maintaining the correct oil level is easy, and choosing the right oil is just as important – explore our range of motorcycle oils to find the perfect fit for your bike.

Fortunately, checking your engine oil is an easy task on almost every motorcycle.

First park your bike on level ground - usually on a centerstand or paddock stand - and leave it for at least 20 minutes to cool down if the engine has been hot, and to allow all of the oil to drain into the sump before carrying out your check.

How to read oil levels with a dipstick

As with checking oil through an inspection window, start by parking your bike on level ground, on a centerstand or paddock stand and waiting for the engine to cool and for all oil to drain back into the sump.
You will find the dipstick low down on one side of the engine. Unscrew it counter-clockwise by hand, and wipe it on a rag or paper towel. Then place it back into the dipstick hole until it is resting on the thread - you don't want to screw it back in at this stage.
Then carefully withdraw the dipstick again to check the level. You should see a lower and a higher mark on the dipstick, sometimes with a cross-hatched area in between.
The oil level should be somewhere between these two marks. However, if it is below the lower line or above the higher line, you need to either top off or drain off some oil.
Assuming that the level looks OK, you should also take this opportunity to assess the condition of the oil. It should be green or yellow, glossy and semi-transparent. However, if the oil is black or dark brown, the oil has been burnt and broken down, which means you need an immediate engine oil change. You should also check for the presence of any thick sludge.
In extreme cases, you may even see particles of metal in the oil, which can indicate engine wear, or the oil may have a milky quality, which can indicate that coolant is getting into the oil. In either of these last two cases, you should consult with a mechanic as soon as possible to determine if your engine has a serious problem.
Before replacing the dipstick, it's a good idea to smear a small amount of oil onto the seal, and to take care to avoid cross-threading the screw when you replace it. So if you encounter any resistance when screwing the dipstick back in, always back it off and try again until you're sure the threads are properly aligned.

How to check motorcycle oil through an inspection window

If your bike is reasonably modern, it will often have an inspection window, low down on one side of the engine. You may have to get close to the ground to see inside properly, and we also recommend doing this in daylight, so you can get an idea of the level and the condition of your oil.

The inspection window will have marks at the top and the bottom, and your engine oil level should be somewhere between the two. If the level is above or below these lines, you must act immediately to either drain a little oil away or to top off your oil level.

Just as importantly, you also need to assess the condition of the oil. It should be either green or yellow, as well as shiny and semi-transparent.

If your oil is dark brown or black and you can't see through it, or you can see sludge deposits, it is definitely time for an oil and filter change.

Alternatively, if you can see metal particles in the oil, this can be an early indication of engine problems ahead; while if the oil looks at all milky, it can often indicate a coolant leak. In either of these two cases, you should consult a mechanic or repair shop to rule out or deal with serious problems as soon as possible.

How often to check motorcycle oil

The rate at which your bike will use engine oil isn't a constant. Environmental factors such as poor fuel quality, extreme temperatures or just spirited riding can affect your bike's oil consumption.

Here at Castrol most of our motorcyclists check their oil level at least once a week, and always before going on a long run or a road trip.

That's because even if you stick religiously to the drain intervals and viscosity of oil recommended by the OEM, even the strongest oil won't protect your bike if the oil level gets too low.

So a weekly oil level check, and a top off whenever necessary, really is a vitally important part of looking after your motorcycle.

Ensuring peak motorcycle performance: Check your oil regularly

Maintaining the correct engine oil level is vital for your motorcycle's health and performance. Whether your bike uses a dipstick or an inspection window, regular checks are essential. Remember to check your oil weekly and before long rides, looking for the correct level and a healthy oil color and consistency. Don't let low or degraded oil compromise your engine – find the right Castrol oil for your motorcycle using our convenient Product Finder and keep your ride running smoothly.