Where is this Oil Leak Coming From?

[ted99]

Hello Everyone,

My bike developed a new oil leak. It leaks onto the header, then almost straight down from there. I can't find the source of the leak. Based on the picture, can anyone tell me who the usual suspects are for this leak? The garage floor is slightly higher at the front of the bike, so the oil is dripping at the top end of the puddle, then going traveling toward the rear. http://ktmsmt.com/download/file.php?mode=view&id=2227

[ted99]

Getting closer to the source. Notice drip forming from above the header?

[Gimlet]

Could be a drive shaft oil seal behind the front sprocket. You need to to take the sprocket cover off, degrease and get everything clean and dry so you can see what's happening.
Might not be. Might be a minor top-end leak that's dripping onto the crankcase and running down making it look like its coming from somewhere else. Clean, fire up and observe.

[ted99]

Thank Gimlet,

I did just that. Although I clean and lube my chain frequently, I never look at the front sprocket. Under the plastic cover was a ton of dirty grease. It was caked in there, pretty thick, so I cleaned it out. Hopefully it's just accumulated chain lube that built up so much it finally had to leak out somewhere. But if it continues to leak now, it's probably from behind the sprocket, as you say.

I just road it into work this morning. After being parked for an hour, there appears to be a drop forming above the header. We'll see what happens over time...

The bike does go through quite a bit of motor oil, but it always has, so I haven't given it much thought.

Thanks for the input, and I'll keep everyone posted.

Ted

[Magic Wand]

Hi ted99

I had something similar on my SMT 2010 some months ago. Oil was coming out from somewhere, and was seen at the exhaust pipe, the shifting lever, under the engine and also on the swinging arm and rear hugger...

My first thought was that the seal on the main shaft axle is worned out, so I replaced it (don´t do it if you don´t have to!), but it was still leaking from somewhere...

The copper washer on the screw above the oil jet was worn out and I simply turned it around and reused it. Yet it´s not leaking...
Suggest you to take out the oil jet and clean it. Then put a new copper washer in place and tight the screw.

/M

[ted99]

Awesome! I'll try that first. Thanks! Weekend project...

[ted99]

After cleaning and drying everything out, it seems like it's leaking oil out the bottom of this. Is that possible? Do I need to replace a seal behind it? I assume this is a sensor?

[jmh]

See this page; http://www.jumph4x.net/post/85791972182 ... l-leak-fix

Same leak.

[ted99]

That's it! And my bike also has 11,000 miles. Amazing. Thank you!

[ted99]

Fixed. It was the O-ring behind the gear sensor. Thanks for the replies!

[Motoproponent]

I have 67,000 miles on my SMT. I've gone through three of those O-rings so far. I suggest you get two or three when it's not leaking and keep it on hand somewhere. It's not a common size and so far I've only been able to source them from a KTM dealer.

It sucks to be not riding, waiting for the shop to open for a $2 part.

[kennykjam]

Thanks to the info in this thread, just replaced the rubber behind the gear position sensor and fixed my own own leak. I wonder how long it had been leaking slowly and just burning up on the exhaust before I eventually noticed it. Maybe the bike will stop using so much oil now


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