DIY! How to Replace the Oil Filter to Protect Your Engine! [YZF-R25 Edition]

How to

The generation of metal dust due to friction has been greatly reduced in the latest engine model with the evolution of materials, improvement of processing accuracy, and improvement of engine oil quality. However, an oil filter is still essential to remove the dirt, or sludge, generated by the degradation of engine oil. The replacement process is easy if you have a cup-type filter wrench.

Oil filter to remove dirt from engine oil

The cartridge oil filter on the YZF-R25 is located in front of the crankcase, and the exhaust pipe is located on the right side of the motorcycle, so removing the left side cowl (behind the blue cowl, the silver part) is the easiest way to remove it.

The engine oil that circulates inside the engine does a variety of jobs in various parts of the engine. It lubricates the gap between the piston and the cylinder and seals the gap between the piston and the cylinder to prevent pressure from escaping during combustion. The cylinder head absorbs the high heat generated during combustion while lubricating the camshaft and valve stem and cooling. It lubricates the gears that engage with strong forces on the crankshaft and transmission as well.

Degradation of engine oil due to mileage and use can be caused by two patterns: viscosity decline and foreign matter formation. The viscosity drop is caused by the additive components in the oil at the points where strong forces are applied to the oil, such as the gears and rotating parts.

The viscosity drop is caused by the additive components in the engine oil at the gears and rotating parts where strong forces are applied to the engine oil. This is caused by the breakdown of the composition. When the performance of viscosity index improver, a type of additive, deteriorates, the viscosity decreases mainly at high temperatures. Low viscosity leads to a decrease in engine oil performance, which is why it needs to be replaced.

Another type of foreign matter formation is dirt generated when fuel is burned. Simply put, these are carbon scum from the fuel or engine oil that has been carbonized at high temperatures. Some of you may have seen carbon on the pistons and combustion chambers when the engine is disassembled. It may be, but it's a mass of dirt called carbon sludge.

When the sludge is mixed in with the engine oil circulating in the engine, the sludges directly damages the lubrication area. But not only that, if it clogs a narrow pathway in the lubrication pathway, called an orifice, the lubrication stagnates beyond that point. It can lead to major problems.

The oil filter is the one that removes that pesky carbon sludge. The filter's eyes are very fine and catches sludge and even small debris. As the amount of dirt increases, the eyes become clogged and the filtration performance deteriorates, so regular replacement is necessary.


  1. Carbon sludge generated by engine oil deterioration
  2. Oil filter to remove debris from the oil

Interval of oil filter replacement is once every 3 times of changing the engine oil.

Exclusive cup-type filter wrenches are available for each filter size. Depending on the filter mounting position, band-type wrenches are also available for various filter diameters. There is, but you want to get a wrench that fits perfectly if you plan to ride your motorcycle for a long time.

What happens if you continue to use an oil filter with a clogged filter?

Even if the clogging progresses to the maximum and the flow rate in the filter section drops to zero, it is still a safety valve. The oil circulation in the engine is not immediately cut off because the relief valve opens. However, if dirty engine oil does not pass through the filter and is allowed to circulate, it can cause wear and damage to the engine's internals. progresses faster, and that's not a good thing. You can't tell how dirty the oil filter is by looking at the filter, so it's important to change the engine oil and replace at the right time.

There are different views on the interval of replacement, but according to the YAMAHA YZF-R25's owner's manual, the interval of replacement is every 15,000km. Changing the engine oil is every 5,000 km or once a year, which means you only need to replace the oil filter once every 3 times of changing the engine oil. If you are concern about your motorcycle, of course, there is no problem if you can change the filter at the same time even if changing the engine oil every time.

The oil filter you replace is safe and secure as long as it is an original manufacturer's part. Products from motorcycle parts manufacturers are also easy to pick up, as long as they are compatible with your motorcycle. However, you may want to be wary of non-branded products that you don't know where they're made from.

If a supplier that manufactures products for a famous brand does not disclose its own brand, it is still a good idea to avoid products that look good on the outside but are completely unknown to the manufacturer.

As explained earlier, the oil filter, which removes carbon sludge, is one of the most important engine components. This is a highly important component. Cartridge type oil filters allow you to see the filter element inside the case and since there is not, it is not possible to guess the performance from the appearance. If the contents of the case are skimpy and the filtration performance is poor instead of very cheap, you risk shortening the life of your engine as a result.

The OEM manufacturer's mark gives a great sense of security even if there is a slight price difference.


  1. Changing the engine oil and filter at the same time is not a problem.
  2. Use OEM manufacturer's parts for reliable quality

Click here to purchase an oil filter for YZF-R25

A special wrench is required to change the cartridge filter.

  1. Depending on the type of wrench, there are 2 types of wrenches: one with a hexagonal section for hanging a box end wrench and the other with a square recessed section where the ratchet handle can be set. This wrench is turned by a ratchet handle, and when the exhaust pipe is in the way of a 4-cylinder engine, it can be used to turn it. An extension bar allows you to separate the filter from the handlebars.

  2. If the filter is loose, the engine oil will drip from the surface where it meets the engine, so place an oil pan receiver under the engine in advance. Also, when the filter is set facing downward (with the female threads facing down), any remaining engine oil inside the body will flow out into the oil pan receiver.

There is a chamfer on the tip of the cartridge filter mounted on the outside of the engine, and it is removed requires a special filter wrench for this size. The tip of the cartridge filter, which is mounted on the outside of the engine, has a chamfer and requires a special filter wrench for this size to be attached and removed. You can buy the size that fits your motorcycle, as it is available from motorcycle equipment manufacturers .

Click here to purchase an oil filter wrench

As long as you have a wrench, changing the filter is easy.

Once the engine oil is drained from the drain bolt, put a bowl-like filter wrench over the oil filter and turn it with a tool. Depending on the wrench, there are 2 types of wrenches: one that can be turned with a box end wrench and one that can be turned with a socket wrench.

Placing an oi pan receiver under the filter/engine mating surface before loosening the wrench will keep the floor clean from spilling engine oil. If you turn the threaded part of the removed oil filter downward, the remaining oil in the case will come out, so when you change the direction of the filter, do so on the oil pan receiver.

Apply a thin coat of engine oil or multi-purpose grease as a large O-ring is set on the filter side of the mating surface with the crankcase in order to prevent oil leakage when installing. This is to prevent the ring from twisting when it is set in the engine, so it is not necessary to apply a thick layer of paint.

If the engine oil is wiped off from the engine and the O-rings are also degreased, they may twist when they come in contact with the seat surface. It will cause poor adhesion and oil leakage. So apply a thin layer of engine oil or multi-purpose grease to the O-rings. There are also filters that are pre-greased with oil.

You can also use a wrench to remove the filter, but you don't necessarily need to use a tool to install it. Unlike STD bolt and nut tightening, if the sensation of crushing the filter O-ring with your bare hands is transmitted, no further torque is needed. On the other hand, if you use a tool and apply enough force to completely crush the O-ring, you may have a hard time the next time you remove it.

For users who do DIY of changing the engine oil, oil filter replacement is a task that can be done with "one more step". To protect your motorcyce engine, why not try using a filter wrench with one hand?

Oil on the filter cartridges and engine can cause contamination and should be cleaned with parts cleaner. Once cleaned, any subsequent oil bleed will be easier to detect.

If you only change the engine oil, the engine oil requirement is 1.8 litres. If you need to replace the oil filter at the same time, the engine oil requirement is 2.1 liters. If you are using a 1 liter can of oil, put 2 liters in and wait a while at idle. Stop the engine and check the engine oil level and adjust it so that the oil level is between the upper and lower limits.


  1. You need a wrench to remove the oil filter.
  2. Apply a thin layer of grease or engine oil to the O-ring.
  3. You can tighten the filter by hand.

See YAMAHA Moto Index Page
See Accessories for YAMAHA YZF-R25 (R25)

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