Goofy exhaust headers

[K7TKA]

I picked up a used exhaust system so I could play without changing my pristine new stuff. After installing the new set I discovered something was making one cylinder fire back through the carb. Today I dropped the new system and the engine runs fine (loud). Upon further inspection I found the right bank had additional tubes built inside the header. It appears to be a very nice factory type job but it is only on the right side. My other set doesn't have anything like it. I'm just wondering if anyone knows why this would be done. I am attaching some photos. The top photo is the stock header.

 

[ekvh]

Best explanation I've heard is: moisture getting trapped between the two thicknesses which is then superheated and with no easy escape, balloons the inner, hotter tubing. I have seen several photos of it and one set in person.

 

[roncar]

AFAIK all GL1000 OEM headers (others???) are double walled. On a good header it is not apparent, to me anyway. Never experienced or seen it myself, but I've seen pics of headers where the inner wall has collapsed causing a restriction. Why does this happen? I don't know but several have theories. The only solution I know of is replacement.

 

[tom foreman]

it,might be a russ Collins.header-pipe.i had a 4-into russ Collins header,on my 78-1000.it never back fired or let me down.i slash cut it.and sounded.like a pack of Harleys coming down the road.it had back pressure tubes inside.my spelling might be wrong.it was 18 years ago..russ Collins was a performace-guy.with Honda,i think..been a long time.. :hi: :music: