Weird sound coming from counter shaft

Hi all

Hoping that some of you might give me a couple of pointers here...

On my bike (a 2012 kx450) there is coming a weird sound from the countershaft when the bike rolls, with engine on or off. It almost sounds like a buzzing. The sound suddenly appeared. And I shut down the engine immediately. Afterwards I also noticed that there was a bit of water in the oil.

Has any of you experienced something similar, or do you know what might be wrong?

Oh. And the buzzing slightly changes character depending on if I hold the clutch in or not.

Edited by Skyrider78

Could be something with the watepump  gasket/axle because you got water in the oil

and the sound on the clutch, the clutch is on the same place so tear it down and check

its pretty easy


And can be like Snowmule says  in the post under 

Edited by skorpan777

Congratulations, sounds like you destroyed a countershaft bearing!


Disassemble, split case, replace bearing, reassemble. 

Did you ride it with the chain too tight?  That'll put massive load on the countershaft bearing and could cook/kill it.


Here is a little update.

When draining the oil we saw that there was way too little oil on the engine.

We assumed it was due to the counter shaft seal, because there was a little oil on thatsideof the engine. In order to find where the sound came from we disassembled the clutch and found that the bearing on the clutch-shaft was running a bit dry. We oiled it up, and now it works perfect again.

The day after we fanged the counter seal. Afterward when inspecting our great work we saw that the generator cover had a hole in it, probably due to a rock or something hitting it. So that is where the leak came from.

Just waiting for a new cover, and then it is once again ready to race.

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