Decat pipe broke today

BLIGHTYBRIT/SF

BLIGHTYBRIT/SF

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Decat pipe broke today
Decat pipe broke today
Decat pipe broke today
I had 80 mile ride this morning & whilst just 5 miles from home a rather loud noise occurred,pulled over and found the r/h side of decat pipe had come clean off,also u can see in the picture s that the mount has broken to.
I’ve got a fabricator guy near me that can do all things fancy with bits of metal ,inc sub contract work of F1,so I intend just to give him the bike to fix at his workshop & see if he can alter the mount anyway with more flexibility to take up the stress/load to prevent it happening again, the mount has broken b4, but that was fixed under warranty, bike now 3 years old on 16,500 miles .
Ken made his own decat pipe using the oringinal cat ,so I may even do that
 
Hello Richard , Its worth a go using the original cat and gut it . And if that one breaks , try the factory New style decat. It may be constructed better than the original type we have.
 
Richard, hopefully it’s an optical illusion, or trick of the light, or just me talking bollox...

But it looks like you’ve got a hole in your sump !
 
It’s all three Nigel, you just made me go outside to a draughty garage & lay on floor in me best 501,s , no a hole,but recess with an Allen bolt head casting a shadow.
Will drop the bike off next few days to my local “Ed China ”got to get bike in shape for two weeks tomorrow,the first catch up of the year of 961 ers at “ Rykas Cafe”
 
Decat pipe broke today


Is it possible this new design will not crack ? You will notice the welded joint where the the curved pipe meets the straight pipe is bridged by the hanger top and bottom. Also , the hanger is two pieces joined about double the thickness of the original. This is what I will get next when mine breaks .
 
Yes it is ! But it is not mine ,. This was posted by italia some time ago. I just think it is built better (to last longer) .
 
TonyA said:
Yes it is ! But it is not mine ,. This was posted by italia some time ago. I just think it is built better (to last longer) .
Click to expand...

I'd say so.
Looks like battleship quality.
Are those slices of bracket plate 1/8" thick?
 
This happened to my Zard exhaust as well. The pipe did not break but the bracket attaching the center of the system to the bottom of the bike snapped . I found out the same way as the OP while riding and hearing a loud sound. Had a friend weld it back together. I just re-installed it yesterday and hoping it does not happen again. But it probably vibrates so much that it will happen again.

When I reinstalled the headers I could not tell if there were crush gasket already in place. I tried to dig out the black ring seated in the spot where the headers get inserted but could not dig it out so maybe there was no crush gasket. I just installed new aluminum crush gaskets in there so I might have 2 in place now. Anyone no if this is a problem? Also when tightening the header bolts how tight is tight enough? And show there be any space beteen the header plate and the engine? Should the plate mount flush to the engine or is a little space OK? Thanks
 
There is a space , thats OK . Do not over tighten. 2 exhaust sealing gasket per side is what I run and prefer . There is a torque spec for the exhaust pipe flange studs . I will find it in the Euro4 service manual . A mere 19NM . After you've driven a week or two check them again for looseness .
 
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Any advice for if ive already overtightened? I haven’t checked the torque but I’m sure I’ve overtightened. And I used high heat thread lock.

To clarify when I took them off the studs came out rather than the nut coming off. So when I say I believe I’ve overtightened, I’ve overtightened the stud into the engine.

I used thread lock because I was hoping next time I took these off, the stud would remain in place and the nut would come off.
 
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Norton messed up and used a stud with a thread on each end and not a through thread or fully threaded stud so the flange cannot actually be fully tightened due to tolerances and dimension stack up. A major over sight by Norton. We always use dual crush.
 
Asad said:
Any advice for if ive already overtightened? I haven’t checked the torque but I’m sure I’ve overtightened. And I used high heat thread lock.

To clarify when I took them off the studs came out rather than the nut coming off. So when I say I believe I’ve overtightened, I’ve overtightened the stud into the engine.

I used thread lock because I was hoping next time I took these off, the stud would remain in place and the nut would come off.
Click to expand...

How over tight? If you used a regular wrench they are different lengths to guide in hand tightening. So maybe not as bad as you think. But if you used a ratchet and a socket then maybe you could really over tighten.
 

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