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Old 12-04-2012, 11:36 AM   #10
Beastly Adventurer
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Joined: Sep 2009
Location: SE Denver-ish
Oddometer: 7,231
Originally Posted by planemanx15 View Post
I'm a little confused with the exhaust dimensions. The end of the header where the stock muffler attaches is 1.135 ID and 1.265 OD? Im looking to build my own cheapo midpipe, and the pipe coming off the Hayabusa muffler is huge, i think over 2".
Those numbers are for the stock muffler

Stock Mufler Inlet:
I.D. = 1.4"
O.D. = 1.51"

Stock Muffler Outlet:
I.D. = 1.135"
O.D. = 1.265"

Years ago I made a midpipe for the DR using 1-1/2" O.D. exhaust tube. It slid inside the stock exhaust pipe with the stock gasket (by your ankle). It was a proper slip fit.

The midpipe from Kientec is 2" O.D. (on the bike now). At the front (ankle), since it uses the stock gasket, I think it is also 1-1/2" O.D. into the stock exhaust pipe.

So I'm guessing that you need to get from 1-1/2" O.D. at the front (exhaust pipe connection), to 2" O.D. to match the Hayabusa inlet. The second pipe in the photo.

Goin' ridin' Be back later to answer any more questions.

From Kientec: (wowie, big pic )

2004 DR650: 62,605 miles
2013 WR250R

Originally Posted by Threewheelbonnie View Post
"BTW, I don't do style. It's a dirt bike, not some girlie dress-up thing." -
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