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Old 05-04-2012, 07:04 PM   #1
mrbindc OP
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R100GS custom exhaust on a R65?

I have a 1982 R65 and I've been thinking about a 2 into 1 exhaust for it. A custom set up for a R100GS just posted on IBMWR and I was wondering how hard it would be to modify it to fit the R65. I know the exhaust nuts are unique on the R65 and there is a thicker metal exhaust gasket but it seems these challenges could be overcome with enough $$ or am I crazy?

Any thoughts?
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Old 05-04-2012, 07:07 PM   #2
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Quote:
Originally Posted by mrbindc View Post
I have a 1982 R65 and I've been thinking about a 2 into 1 exhaust for it. A custom set up for a R100GS just posted on IBMWR and I was wondering how hard it would be to modify it to fit the R65. I know the exhaust nuts are unique on the R65 and there is a thicker metal exhaust gasket but it seems these challenge could be overcome with enough $$ or am I crazy?

Any thoughts?

I like crazy. Really I do ... the GS exhaust head is 38mm. The R65 is 36. The length will be a problem too, as the R65 is a 'short wheelbase.

Not impossible ...

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Old 05-04-2012, 07:12 PM   #3
Airhead Wrangler
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The bigger issue that you'll have is that the R65 engine is about 2.5" narrower (shorter stroke) than the R80/100 engine and the exhaust ports are closer together. Headers from the R100GS might just hit the oil pan before you can even fit them into the exhaust ports. I don't know this for sure as I've never tried it, but that's what I would guess.
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Old 05-05-2012, 12:34 AM   #4
Boxer Metal
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If you use the R65 headers coming out of the heads(about 12" of it), then into the GS header, get rid of the presilencer for a Y pipe and open up the GS muffler a bit you might have a good flowing exhaust.
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Old 05-05-2012, 02:02 PM   #5
mrbindc OP
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thanks for the inputs. I like the idea of using the R65 header to make it adapt.

I could modify the header pipe with 6-12" of my R65 header. Once it was welded up and installed I could use exhaust wrap back to the collector to cover up the joint and make it less obvious. I planning to do a mild scrambler build with this bike so the upswept muffler is ideal.

this custom GS exhaust is actually 5 pieces, there are 2 headers, the 2 into 1 collector, and it uses a Supertrapp 10 disk muffler.
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Old 05-05-2012, 02:09 PM   #6
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Quote:
Originally Posted by mrbindc View Post
thanks for the inputs. I like the idea of using the R65 header to make it adapt.

I could modify the header pipe with 6-12" of my R65 header. Once it was welded up and installed I could use exhaust wrap back to the collector to cover up the joint and make it less obvious. I planning to do a mild scrambler build with this bike so the upswept muffler is ideal.

this custom GS exhaust is actually 5 pieces, there are 2 headers, the 2 into 1 collector, and it uses a Supertrapp 10 disk muffler.
Your R65 exhaust will slip right into the GS exhaust. Do more than 6".
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