Help identifying Kx125 oil leak

Just picked up a 2005 KX125. New to bikes so take it easy on me. :)

This is situated on the kickstart side, between the cylinder head and the crankcase. Inside the rubber boot seems to be a thin shaft going up and the round bit is covering a "button".

What am I looking at here and what's the likely cause of the leak?


Edited by Nuzzie

Thats for your powervalve linkage, make sure your breather hose on the left side of the cylinder isnt plugged. That's where all the extra oil that builds up inside of the powervalve drains out of.

Cheers buddy, I will check that as soon as I can. Thanks for the quick reply.

Edited by Nuzzie

What he said, plus you may want to check inside for excess oil and clean it out a little.

Congratulations on getting a 2005 KX125.

Checked the hose last night and it was kinked where it came out of the exhaust valve compartment, and one of the cable ties tying it to the frame was done up quite tightly. Blasted it with brakleen and compressed air anyway but nothing seemed to be blocked up in there.

If I open it up is it alright to blast it with brakleen or a degreaser? I'll see about doing that tonight.

I would skip the blasting, maybe a paper towel sprayed with cleaner. No need to splash it everywhere.

Didn't seem to be because the hose is kinked it's still leaking quite excessively. Seems to be gearbox oil too as the level of that looks like it's been going down.

I'm taking it out of commision to replace fork seals and and a new top end soon, so I'll look into it a bit more once I've got the head off.

Well you probably have a lot of excess oil built up in that boot.Its not really a tight fit on that linkage so any that is left inside will just leak out. And just take the breather hose of and clean it if you want. All it takes is a ziptie to put it back on.

2 separate problems?? I am not sure.

Good luck with it.

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