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Exhaust pipe seals
Posted: Thu Jul 30, 2015 9:05 am
by lutorm
Hey guys,
I have a problem with my NC30: I can't get the front pipe to collector joints to not leak. I don't know if there's a trick or if my pipes have been abused, but the sealing "cylinders" don't fit into the collector sections past where the "cutout" is. It's like the collector sections have been clamped down past the cut out section so it's too small for the seals. This means the seals only sit over the split section which of course gives a leak at the cutout.
Are the collector section pipes supposed to be perfectly even from the split to the unsplit section? Mine have a definite joggle where the split ends. It may be they're just out of round, but it's enough to not get the gasket into it.
Any ideas?
Thanks!
/Patrik
Re: Exhaust pipe seals
Posted: Thu Jul 30, 2015 9:21 am
by Dynamohum
A picture might explain what you are describing but from what your saying it sounds like the mild steel sections on the exhaust where the gaskets sit for the front pipes to rear section have rotted gone altogether

Re: Exhaust pipe seals
Posted: Fri Jul 31, 2015 6:22 am
by lutorm
The front sections are fine. It's the rear (outer) sections that are the problem. A picture is a good idea:
link
See how the seal won't fit into the rear section fully, leaving a gap at the cutouts.
Re: Exhaust pipe seals
Posted: Fri Jul 31, 2015 1:57 pm
by Dynamohum
From the pic it looks like the part where the gasket sits has been replaced at some point with new sleeves normally this does away with the original Honda gasket and you just clamp it up with some exhaust paste/silicon etc what sort of fit are you getting without using the gaskets ?
Re: Exhaust pipe seals
Posted: Sat Aug 01, 2015 5:57 am
by lutorm
Nah, without the seals there's a mile wide gap. There's no sign of this being replaced, the welds and the material look just like on the rest of the pipe, so I'm pretty sure it's the original.
Re: Exhaust pipe seals
Posted: Sat Aug 01, 2015 11:03 am
by Dynamohum
If that's the original then they are in remarkable condition most have rotted away by now the gaskets are a tight fit on them anyway . Only thing I can suggest is giving them a thorough clean inside removing any carbon deposits etc and if there misshapen try gentle use of a socket of the correct size to get them back in shape then fit the gaskets onto the front pipes with the rear section bolted on apply some grease inside and onto the front pipes at the gasket and try gently working the fronts on .
The gaskets are a kind of coated wound matererial if too much force is used they will fall apart so be gentle .
Perhaps someone can confirm from the picture that these are indeed the original mid joints it's been that long since I've seen some .
Re: Exhaust pipe seals
Posted: Sat Aug 01, 2015 3:42 pm
by Neosophist
they dont look lke original nc30 joints to me. They look like theyve been replaced.
But, ive recently replaced gaskets on my bike, i had to widen them up and tap it in but it was an easy fit.

Re: Exhaust pipe seals
Posted: Sun Aug 02, 2015 5:18 am
by lutorm
Hmm yeah they don't look like those ones, so maybe you're right. I've only seen mine, so it's perfectly possible. I guess that makes me feel better about violating them...
In fact, my entire exhaust looks quite different. I guess it's an aftermarket:
link. (Ignore the bungs for the wideband sensors, I'm in the process of welding those on...)
Re: Exhaust pipe seals
Posted: Sun Aug 02, 2015 1:51 pm
by Neosophist
thats an aftermarket system.
many dont use seals in them, just tight fit, so maybe no need to butcher it.
perhaps put some silicon around them to seal them together.
Re: Exhaust pipe seals
Posted: Mon Aug 03, 2015 4:33 am
by lutorm
Ok, good to know. Without any seals, the gap is many millimeters, that's a no starter.