Last year, an old motorcycle was repaired. It was a NF125 motorcycle, which may not be familiar to many people. It was a two-impact motorcycle. The car has a range of more than 30,000 kilometers, not much. The owner of the car has come to change the oil.

When I was about to change the oil in the gearbox, I noticed that the oil in the gearbox had increased rather than decreased. What's going on here? If anything goes wrong, it's a monster!

In accordance with the provisions of the oil change, told the owner of the situation, asked him to pay more attention to check the oil, if there is an increase in the phenomenon to come to me for a thorough check. After a few hundred kilometers of driving, the owner took down the gauge to check and found that the oil in the gearbox had increased. At the same time, he noticed that the oil in the oil tank was running out fast.

So the owner came to check on me as promised. From the fault phenomenon, it is estimated that there is a leakage phenomenon in the lubrication system. Since the NF125 oil pump is mounted on the right cover, an organic oil pump shaft seal is installed between the oil pumps to prevent oil from flowing into the gearbox.

If the oil seal is aged, fails, or poorly sealed, the oil in the oil pump will flow into the gearbox, which will have more and more oil in the gearbox, and at the same time, the oil in the gearbox will be consumed very quickly.

Open the right small cover on the right cover and remove the oil pump. Then remove the right cover, then remove the transmission gear and worm of the oil pump from the right cover, remove the oil seal of the oil pump shaft for inspection.

It was found to have aged and failed. After the oil seal of the oil shaft of the oil pump is changed, the right cover and the oil pump are reinstalled. After checking, it is delivered to the car owner, and the owner is ordered to check regularly again. After telephone follow-up, the car did not appear in the increase in oil driving phenomenon, to determine the troubleshooting.