Engine oil change

First, remove the side cowls and panels etc. in order to remove the drain bolts and oil filter.
In the photos below, both the left and right sides are removed, but the work can be done by removing only the right side.

(For information on how to remove the side cowls and panels, etc., see below).

あわせて読みたい

How to remove side cowls and panels etc. 1. Appearance is very good, but… The number of cowls and panels on the YZF-R125 (5D7W)- five on each side and ten on the left and right sides – is outstand…

＜Engine oil leakage condition＞

I have left it for a few weeks after wiping the oil off, but from the drain bolt, very little oil has seeped through.

When the engine was started and warmed up before the oil was changed, the oil gradually leaked out.

Now, I will start to drain the engine oil.

＜Remove oil filler cap＞

Twist off the oil filler cap to allow oil to drain easily.

As described in event “Delivered YZF-R125 5D7W!”, the attachment that prevents engine oil from dripping onto the muffler was not included.

＜Put oil tray and flexible funnel＞

Therefore, use a flexible funnel.
Laying down the flexible funnel also prevents burns from accidentally touching the muffler.

Also, although I use an oil tray out of habit, it is easier to clean up afterwards if I lay the oil pack directly on them.

＜Remove drain bolt 1＞

Loosen the drain bolt with a spinner handle fitted with a socket (19 mm).
It has loosened without being tightened particularly tightly.

The drain bolt has a special shape, with a projection around the central hexagon.
I used a socket wrench because I felt that a ring spanner would not be able to hang on tight enough.

＜Remove drain bolt 2＞

Replace the socket with a quick spinner and loosen the drain bolt by hand.
There is a 3 mm gap between the crankcase and the drain bolt, but no engine oil spills out.

The photo shows bare hands, but in reality, oil gloves are worn.
Be aware that immediately after driving, hot oil may get on your hands and burn you.

＜Engine oil drain＞

When the drain bolt is removed, oil comes out vigorously.

The flexible funnel is doing a good job.

＜Drain bolt fitting＞

The drain bolts are sealed with O-ring.
The sealing surface of the crankcase are very clean and there was no damage to the crankcase that would cause engine oil to leak.

＜Removed drain bolts etc.＞

The drain bolt consists of four parts, from left to right

• Strainer
• Spring
• O-ring + drain bolt

The strainer is supposed to remove large debris, but I feel it can also be removed by the oil filter.
For what purpose?

Now, remove the oil filter.

＜Remove oil filter cover 1＞

Using a T-bar handle with a socket (8 mm), loosen the three bolts fixing the oil filter cover.

＜Remove oil filter cover 2＞

Only the bottom right bolt is longer.

＜Remove oil filter cover 3＞

Remove the oil filter cover by hand.
The oil filter comes off together.

＜Condition of oil filter removed＞

When the oil filter is removed, it is empty inside.
So, the oil filter is only fixed by pressing the rubber parts on both sides.

Three O-rings are used to seal the engine oil, and these will also be replaced.

＜Remove O-ring＞

Remove the O-ring with an O-ring pick tool.

＜Condition of oil filler cap＞

There was black debris on the part where the oil filler cap and O-ring touch.
Has the plastic of the oil filler cap peeled off?

＜Condition of drain bolt＞

I was surprised when I removed the O-ring from the drain bolt.
The sealing surface is quite rough.
Circumferential irregularities like those on a record disc are still there, but the radial scratches are not acceptable.

What is the condition of your drain bolt?

＜Parts cleaning＞

Clean the removed parts with parts cleaner.
Clean off any spilled engine oil on the drain bolts and oil filter cover.

＜O-rings comparison＞

Upper: Removed O-ring
Bottom: New O-ring, Genuine part

From left,

• O-ring for oil filler cap / 93210-19X00
• O-ring on drain bolt / 93210-34802
• O-ring for oil filter cover / 93210-53801

The size of the O-ring for the oil filler cap is clearly different.
Did the specification change during the process or did the previous owner put a different O-ring?

The O-ring for drain holt at the middle had a square cross-section.
Perhaps never replaced?

＜Apply silicon grease＞

The sealing surface of the drain bolt was rough, so more silicon grease was applied to the O-ring.

The strategy is to fill the rough areas with silicon grease.

Now, fit the O-ring.

＜Condition of O-ring installed＞

It fitted like this.
As it doesn’t have too many scratches on other parts, it looks and feel new.

＜O-ring on oil filler cap＞

As the O-ring on oil filler cap has a large inner diameter, it moves.
It does not come off, but it does not fit well and if I am not careful, I may crush it at an angle when tightening.

＜Oil filters Comparison＞

Left: Removed oil filter
Right: New oil filter, genuine part – 30g

The one I removed is probably an external part as the shape of the disc holding the filter is different.
I intend to try different manufacturers in the future.
I don’t think I’ll be able to tell the difference.

＜Mounting surface cleaning＞

Clean the oil filter cover and the oil inlet fitting with a paper towel so that the O-ring does not get caught in dirt.

The condition of the sealing surface is very different from the drain bolt.
The sealing surface has to be like this, otherwise I’m worried that it will leak someday.

＜Install oil filter＞

Install the oil filter.
The one with the hole in the middle should be facing you.

If you put it on backwards, the filter cover cannot be tightened, so you can’t go wrong.
(I tried it, so there is oil on the rubber part in the front.)

＜Install oil filter cover 1＞

Put the socket (8 mm) on the quick spinner and tighten the three bolts evenly by hand.

＜Install oil filter cover 2＞

Then, using a torque wrench, tighten to 10 Nm.

＜Install drain bolt 1＞

Tighten the drain bolt while pressing down on the spring by hand.

Be careful not to hang the threads at an angle.

＜Install drain bolt 2＞

Attach the socket (19 mm) to the quick spinner and tighten the drain bolt by hand.

＜Install drain bolt 3＞

Use a torque wrench and tighten to 32 Nm.

＜Engine oil comparison＞

Left: Drained engine oil
Right: New engine oil, Yamaha Standard Plus

The oil drained is almost new oil.
It has only been run for a few dozen kilometers since delivery, so it is hardly dirty.
It is a waste, but it will be treated as waste oil.

＜Engine oil filling＞

Pour new oil into the filling port.

Quantity of oil required,

• When replacing oil only: 0.95ℓ
• When replacing the oil filter: 1.00ℓ

After pouring in about 0.90ℓ, the engine was started and stopped, and the oil was added little by little.

A 1 litter can is enough, so it’s easy on the wallet.
You can pour it in with the nozzle provided, so it’s easy to work with.

＜Oil level＞

I was too lazy to take photos and lost track of the levels.
I got in about where the line was.

＜Around the oil filter cover＞

Clean the spilled engine oil with parts cleaner and finish.

＜Engine underbody＞

The engine oil leak has now been successfully eliminated.
Possible causes of leakage are below.

• Deterioration of the drain bolt O-ring
• Roughness of the sealing surface of the drain bolt

Finally, put the removed side cowl panels etc. back on.

(See below for information on how to put the side cowl panels etc. back on).

あわせて読みたい

How to install side cowls and panels etc. 1. Some small precautions for installation Here is a list of things to look out for when installing that I may not have noticed when removing.Have you experi…