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exhaust keeps leaking
Posted: Mon Jun 22, 2009 3:34 pm
by druist
I bought a SS Scootrs a few years back and after a time it leaks the lovely black gunge, either at the downpipe join - which put exhaust paste inside after the first time, then at the cyl manifold join, then silencer end, i keep patching and using exhaust paste but eventually it finds it way out somehow.
I even thought of welding the join up, but then i am sure it will just come out somewhere else. Saw some stuff called Permatex copper high temp. But i dont want to keep throwing money at it if i am going to keep getting the same problem
any ideas?
Re: exhaust keeps leaking
Posted: Mon Jun 22, 2009 8:26 pm
by red ghost
Re: exhaust keeps leaking
Posted: Tue Jun 23, 2009 9:48 am
by druist
thanks will give it a go

Re: exhaust keeps leaking
Posted: Tue Jun 23, 2009 10:34 am
by bristolmod
hows it going Drew?
Chris
Re: exhaust keeps leaking
Posted: Tue Jun 23, 2009 1:17 pm
by Special X
If you use clear silicone sealant (the sort used in kitchens and bathrooms that smells of vinegar as it goes off) on the gasket, the slip joint, and the rear can joint it'll seal it ok. Nice and flexible too. Exhaust sealants that set hard are no good for this kind of job.
Re: exhaust keeps leaking
Posted: Tue Jun 23, 2009 1:36 pm
by vegansydney
Yep, what Special X said, silicon sealant. If it's good enough for 2 stroke MX racing then good enough for an obsolete Italian ladies shopping moped.
Re: exhaust keeps leaking
Posted: Tue Jun 23, 2009 2:28 pm
by dapper
It's worth checking that the exhaust manifold face is perfectly flat, that you use solid copper gaskets, and that the brass nuts/washers don't bottom out on the threads, thereby leaving a gap through which you can leak. If you have a machine shop you can go to, get the face of the exhaust manifold milled/machined so its perfectly flat. Then as Special X states use silicone sealant.
Re: exhaust keeps leaking
Posted: Tue Jun 23, 2009 6:52 pm
by druist
bristolmod wrote:hows it going Drew?
Chris
Chris, thanks for asking mate, I am still a little f**ed up from being knocked off my motorbike, just shoulder probs physically and a lot of confidence issues of people waiting at junctions to leap out at me - even while i am in a car. Scooterwise havent had anychance since the accident. But doing something with it daily.
The nuts on the manifold have come loose with only 100 mi. I saw a similar way to doing the chain guide up eg bent over washer for the exhaust flange.
see your pm
SX and Dapper, thanks, have ordered some of that, thinking of using my heavy copper gasket. remember of the LCGB site Martin (Knowledge) saying something about heating the thick ones up first anyone know of this??
Re: exhaust keeps leaking
Posted: Wed Jun 24, 2009 10:40 am
by Special X
Silicone will work great with the thick copper gasket just heat it with a blowtorch until it's showing blue and let it cool. This will soften it and it'l deform to fit the flange faces.
Hope your shoulder gets better soon . . . it's right to expect cars to pull out on you.
Re: exhaust keeps leaking
Posted: Wed Jun 24, 2009 12:50 pm
by druist
^thanks mate. Trouble is i always expect people to pull out, thats why i try and make eye contact which i did, she must have been on another planet though.