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Exhaust leaks
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Author:  safetyfast [ Tue Jul 23, 2013 5:55 pm ]
Post subject:  Exhaust leaks
The exhaust is leaking around where the pipe attaches to the manifold on my MT250. When I installed it, it didn't feel like it went on tight. I've tried tapping it on with a deadblow hammer to no avail. Is there some trick to getting a tight fit?

I've got another kind of leak as well. I noticed oil drips from the exhaust. I sandblasted the exhaust and repainted it. Looked good with no apparent holes. Turns out there are two tiny pinholes that I didn't see. They only leak when the exhaust is hot.
Author:  4x4_Welder [ Tue Jul 23, 2013 8:57 pm ]
Post subject:  Re: Exhaust leaks
There is supposed to be a ring to seal the pipe. Before I fixed mine, it made a greasy buildup on the jug and frame below the pipe. I also picked up almost 5mpg when I sealed that, and lost the greasy goop on the exhaust outlet as well.
Author:  safetyfast [ Wed Jul 24, 2013 5:04 am ]
Post subject:  Re: Exhaust leaks
The ring is there, just cant seem to get the pipe to seal over it.
Author:  rayivers [ Thu Jul 25, 2013 4:44 am ]
Post subject:  Re: Exhaust leaks
There's actually three rings (see diagram). The best way to get a good seal is to pull it apart, clean everything and replace at least the ring gasket (item 7), then reassemble with hi-temp compound on everything and strong springs (if they pop right on, they're too weak). The MT I worked on had the tapered sealing ring (item 5) carbon-welded to the pipe flange crooked, so the new ring gasket just squashed up on one side and leaked like crazy on the other. The piston-ring thing (13) seems to be mainly for mechanical centering, it sure doesn't seal worth a damn.

You could also try just compounding it, but that didn't work too well for me. JB Weld should seal any leaks; I used it on my MR's head pipe and it worked great.

Ray

Attachment:
Exhaust Flange - Manifold Diagram.jpg
Exhaust Flange - Manifold Diagram.jpg [ 28.48 KiB | Viewed 6327 times ]
Author:  safetyfast [ Thu Jul 25, 2013 5:21 am ]
Post subject:  Re: Exhaust leaks
That explains it. Thanks Ray!
Author:  mbilder [ Wed Aug 07, 2013 7:32 pm ]
Post subject:  Re: Exhaust leaks
What do parts 5 and 7 look like? Is 5 a material type gasket similar to plumbers tape? Is number 7 a copper ring? Any ideas where to find these still, or something that will substitute?
Author:  rayivers [ Thu Aug 08, 2013 6:32 am ]
Post subject:  Re: Exhaust leaks
Part 5 is a machined steel collar- I think its function is to compress part 7 (asbestos-looking ring gasket) onto the end of the exhaust manifold.

CMSNL has both of them, I believe:

http://www.cmsnl.com/products/collarex- ... 325358303/

http://www.cmsnl.com/products/gasket-ex ... 352358000/

Ray
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