Possible rear exhaust gasket leak.

[Dunn-y]

For a while now I've had a sort of tapping noise coming from the rear of the bike near the CCT/exhaust pipe. I had the CCT replaced with one that was in good working condition but I still have the exact same noise. Now I can't tell for sure but to me out sounds more like its coming from the exhaust than the CCT.

IIRC its only noticeable at idle, maybe because the sound of the exhaust drowns it out and I don't think its that noticeable at idle once the bike is fully warmed up.

Also on occasion when I pull the clutch in to change gear I sometime get a small back fire out the exhaust.

Is there an easy way to test whether or not the gasket had deteriorated without removing the exhaust?

I'm going to be cleaning my bike tomorrow so will get a video of the noise.

[Spanner Man]

Good morning.


It sounds like you have a leak where the exhaust downpipe joins the short pipe that comes from the cylinder head.
With a ball of rag, have an assistant cover the outlet from the silencer, you may then hear the exhaust blowing at the joint in question.
You will have to remove the exhaust collector, & front pipe to change it I'm afraid. So, start soaking everything with a good penetrating oil.

As yours is a Curvy model, it's highly likely that the nuts on the front exhaust pipe studs will have rusted to the point where a socket wont grip them. If so, you may need a small grinder, or belt sander to sand/grind the nut away to the point where you can 'peel' it off the stud using a small punch.
Don't break the stud! They're a Beggar to drill out.


Cheers.

[Dunn-y]

Thanks for the info. I don't have any of the tools I would need if the studs were to snap and I'm guessing new gaskets will be needed to if I have to remove the pipe. I'm going to try find out exactly what's leaking then price up some new gaskets and studs. I t may have to wait till next month when I have the money for all that.

[Dunn-y]

In the process of cleaning all the road salt off the bike along with an oil change. When I started up the bike earlier the tapping noise is loudest underneath the bike. So almost definitely an exhaust leak of some kind. Now I just need to find exactly where the leak is.

[pookie]

I noticed there are 2 gaskets which are 10 - 15 gbp each I think. One is at the rear pipe by the rear shock and the other is on the underside of the engine by the kick stand.

[Dunn-y]

Something else I noticed is that where the front pipe connects to the collection box thing I don't have a clamp there but pictures of other Curvys do. Think I might buy a clamp and see if that is what's causing the leak.

[Dunn-y]

Am I right in thinking that I should have an Exhaust Clamp here? (Just below the bolt on the clutch cover) http://forums.sv650.org/picture.php?albumid=864&pictureid=6056

[pookie]

yes there should be.. there is one on mine

http://sv650org.homeip.net/images/sv650/ex1.jpg

[maviczap]

Am I right in thinking that I should have an Exhaust Clamp here? (Just below the bolt on the clutch cover) http://forums.sv650.org/picture.php?albumid=864&pictureid=6056

Yes, there should be, but its probably rusted solid, so won't need a clamp.

Its possible that its corroded through around this area somewhere as it collects all the muck and water from the front wheel

[Dunn-y]

To me it sounds loudest underneath the bike near where the collector is. It makes a tapping noise. According to a mechanic I spoke to an exhaust leak wouldn't make a tapping noise but videos of leaking manifolds, on cars, that I have watched have a very desitinct metallic tapping noise similar to mine. It doesn't sound as though it's coming from the engine, or the CCT. Had a look today and couldn't see any noticeable holes in the exhaust but then I wasn't able to see all of it. My question is before I spend more time looking, is can an exhaust leak make an almost metallic tapping noise?

[maviczap]

I'd expect to make a sort of farting type noise, the exhaust on my campervan has split on a seam and makes this kind of farting noise. :p

[Spanner Man]

To me it sounds loudest underneath the bike near where the collector is. It makes a tapping noise. According to a mechanic I spoke to an exhaust leak wouldn't make a tapping noise My question is before I spend more time looking, is can an exhaust leak make an almost metallic tapping noise?


Yes it can. Do the ball of rag trick I detailed earlier, & go from there.


Cheers.

[Dunn-y]

This is annoying me. I cant pin point where exactly this noise is coming from and once the bike has warmed up after a couple of miles, if that, the noise is non-existent.

[Dunn-y]

If possible, I would like to know what can cause a noticeable tapping noise when the bike is cold which then disappears once it has warmed up.