dynojet upgrade/cobra 4 stroke exhaust

DSN_KLR650
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Zachariah Mully
Posts: 1897
Joined: Fri Apr 28, 2000 7:50 am

dynojet upgrade/cobra 4 stroke exhaust

Post by Zachariah Mully » Thu Oct 05, 2000 8:45 am

    I will have to agree with Steve on this one... The PO of my bike had put on a Cobra ISDE pipe and when I bought the bike I had the choice of the Cobra or a Supertrapp (not sure what model), but I didn't know any better. So I kept the Cobra. BIG mistake.     My riding buddy and fellow lister Robb Seurkamp noticed that my exhaust was awful loud and seemed to be getting louder, so we dismantled the exhaust one day with plans to repack it with some of that MSR quiet core packing material. When we finally got the exhaust tip off, we saw that there was no packing in the muffler at all, in fact it was perfectly clean. You'd think that there would be something left over (muffler had about 3k miles on it at that point). Anyhow Robb and I couldn't get the frickin' collector/baffle thing out even with some concerted hammering...     So we assembled it without repacking it as I wasn't sure if it was supposed to be repacked. A couple weeks later (and about 500 miles) after working on the exhaust, I pulled the side panel off for some reason and saw that the aluminum can on the Cobra had discolored to a reddish brown, swollen like a grapefruit and had begun to bubble (looks like the exhaust has some serious disease). The can no longer fits on the triangular pipe (between the can and the header pipe) and the triangular pipe no longer mates with the header pipe. I haven't called Cobra about this, but I am hoping they will replace this as this is clearly unacceptable.     My recommendation: Do NOT by a Cobra regardless of how cheap it is.   Zack 1991 KLR650 "Buster" 1986 Concours   P.S. Anyone want to by a FU'ed Cobra exhaust ;)  -----Original Message----- [b]From:[/b] Steve Swedhin [mailto:stevens@...] [b]Sent:[/b] Thursday, October 05, 2000 6:52 AM [b]To:[/b] DSN_klr650@egroups.com [b]Subject:[/b] [DSN_klr650] RE:Dynojet upgrade/Cobra 4 stroke exhaust
[quote] It is actually a piece of junk, I don't know what the Supertrapp is like so I can't give you a comparison there. The Cobra 4 Stroke has some major design flaws - the housing is aluminum, the collector inside is made of steel and is pressed in. This alone creates two problems - dissimilar metal corrosion and heat expansion differences. What happens is that the steel doesn't expand/contract as much as the aluminum and the aluminum ends up being streched and will allow the collector to rattle around. This will eventually beat the aluminum until it splits in two. In addition the only thing holding the guts tight is the snap ring outside and a spring inside. (My other bitch) I know I've had two of them one bought and one factory replacement. I have E-mailed them with my concerns and disgust and so far received no reply. Not to side with Elden Carl, but as far as I'm concerned stick with stock. He's right on this subject.                                     Steve "Swede" Swedhin. Visit the KLR650 archives at http://www.listquest.com/lq/search.html?ln=klr650 Support Dual Sport News... dsneditor@... Let's keep this list SPAM free! Visit our site at http://www.egroups.com/group/DSN_klr650 To unsubscribe from this group, send an email to: DSN_klr650-unsubscribe@egroups.com
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