Leaking exhaust

I’m quite new to the off-road scene and in particular to 2 strokes ( first off road was a KLX 450R).

After riding today I noticed a black substance leaking where the header pipe meets the tail pipe and as is evident from the photos.



i) What is the black substance and should it be a course of concern?

ii) Will the leak in the exhaust effect performance?

Well now!! It's a the well documented curse of spooge and most likely due to a carb that's in need of some proper jetting. There are a number of threads in this forum that deals with this and if you go to the sticky at the top of the page you will easily locate that(happy reading). It's been my experience that having spooge go away completely is very rare, although some on here will tell you theirs are almost nil. Once you get the jetting straightened out you probably should still deal with that joint to lessen the spillage on the swing arm, remove the little springs and replace with small zip ties. One other thing, you should repack your silencer once you get your jetting close.

Hope this helps.

Yea jetting will eliminate that for sure, but in the meantime you can fix this so that it seals better and all you need is some kerosene and a wire brush.

I've told a few people this and it works.

Take the silencer off and remove the rubber grommet and remove both the springs. Soak the springs in kerosene to clean them up and the rubber grommet as well. Flip the grommet inside out and clean it well, you'll know it's clean because it will go back to the original greyish color like when it was new. Once all the oil is rinsed and scrubbed off the grommet should have it's rubbery feel back and will seal much better now, if you see any cracks then it's time to get a new one.

I did it to mine and it sealed like new again.

Thanks, will do.

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